diff --git a/docs/html/README_8md.html b/docs/html/README_8md.html
index 5267418..690149b 100644
--- a/docs/html/README_8md.html
+++ b/docs/html/README_8md.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: README.md File Reference</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -99,7 +99,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="README_8md.html">README.md</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/cppbaseAll_8hpp.html b/docs/html/cppbaseAll_8hpp.html
index 23d94a2..88a7754 100644
--- a/docs/html/cppbaseAll_8hpp.html
+++ b/docs/html/cppbaseAll_8hpp.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: cppbaseAll.hpp File Reference</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -112,7 +112,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li><li class="navelem"><a class="el" href="dir_d1bd97ed40e89648596a0852aac26258.html">cppbase</a></li><li class="navelem"><a class="el" href="cppbaseAll_8hpp.html">cppbaseAll.hpp</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/cppbaseAll_8hpp_source.html b/docs/html/cppbaseAll_8hpp_source.html
index 5cc3b99..486268b 100644
--- a/docs/html/cppbaseAll_8hpp_source.html
+++ b/docs/html/cppbaseAll_8hpp_source.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: cppbaseAll.hpp Source File</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -51,6 +51,11 @@
 /* @license-end */
 </script>
 <div id="main-nav"></div>
+<script type="text/javascript">
+/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
+$(document).ready(function() { init_codefold(0); });
+/* @license-end */
+</script>
 </div><!-- top -->
 <div id="side-nav" class="ui-resizable side-nav-resizable">
   <div id="nav-tree">
@@ -109,7 +114,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li><li class="navelem"><a class="el" href="dir_d1bd97ed40e89648596a0852aac26258.html">cppbase</a></li><li class="navelem"><a class="el" href="cppbaseAll_8hpp.html">cppbaseAll.hpp</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/dir_d1bd97ed40e89648596a0852aac26258.html b/docs/html/dir_d1bd97ed40e89648596a0852aac26258.html
index fd64b96..5481e0f 100644
--- a/docs/html/dir_d1bd97ed40e89648596a0852aac26258.html
+++ b/docs/html/dir_d1bd97ed40e89648596a0852aac26258.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: cppbase Directory Reference</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -116,7 +116,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li><li class="navelem"><a class="el" href="dir_d1bd97ed40e89648596a0852aac26258.html">cppbase</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/dir_d44c64559bbebec7f509842c48db8b23.html b/docs/html/dir_d44c64559bbebec7f509842c48db8b23.html
index 542d5b1..be75656 100644
--- a/docs/html/dir_d44c64559bbebec7f509842c48db8b23.html
+++ b/docs/html/dir_d44c64559bbebec7f509842c48db8b23.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: include Directory Reference</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -105,7 +105,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/doxygen.css b/docs/html/doxygen.css
index 0caa19b..009a9b5 100644
--- a/docs/html/doxygen.css
+++ b/docs/html/doxygen.css
@@ -1,4 +1,4 @@
-/* The standard CSS for doxygen 1.9.7*/
+/* The standard CSS for doxygen 1.9.8*/
 
 html {
 /* page base colors */
@@ -152,6 +152,11 @@ html {
 --tooltip-declaration-color: #006318;
 --tooltip-link-color: #4665A2;
 --tooltip-shadow: 1px 1px 7px gray;
+--fold-line-color: #808080;
+--fold-minus-image: url('minus.svg');
+--fold-plus-image: url('plus.svg');
+--fold-minus-image-relpath: url('../../minus.svg');
+--fold-plus-image-relpath: url('../../plus.svg');
 
 /** font-family */
 --font-family-normal: Roboto,sans-serif;
@@ -298,8 +303,8 @@ html {
 --code-char-literal-color: #00E0F0;
 --code-xml-cdata-color: #C9D1D9;
 --code-vhdl-digit-color: #FF00FF;
---code-vhdl-char-color: #000000;
---code-vhdl-keyword-color: #700070;
+--code-vhdl-char-color: #C0C0C0;
+--code-vhdl-keyword-color: #CF53C9;
 --code-vhdl-logic-color: #FF0000;
 --code-link-color: #79C0FF;
 --code-external-link-color: #79C0FF;
@@ -320,6 +325,11 @@ html {
 --tooltip-declaration-color: #20C348;
 --tooltip-link-color: #79C0FF;
 --tooltip-shadow: none;
+--fold-line-color: #808080;
+--fold-minus-image: url('minusd.svg');
+--fold-plus-image: url('plusd.svg');
+--fold-minus-image-relpath: url('../../minusd.svg');
+--fold-plus-image-relpath: url('../../plusd.svg');
 
 /** font-family */
 --font-family-normal: Roboto,sans-serif;
@@ -481,6 +491,12 @@ div.qindex{
 	color: var(--index-separator-color);
 }
 
+#main-menu a:focus {
+	outline: auto;
+	z-index: 10;
+	position: relative;
+}
+
 dt.alphachar{
 	font-size: 180%;
 	font-weight: bold;
@@ -679,6 +695,18 @@ div.line.glow {
 	box-shadow: 0 0 10px var(--glow-color);
 }
 
+span.fold {
+        margin-left: 5px;
+        margin-right: 1px;
+        margin-top: 0px;
+        margin-bottom: 0px;
+        padding: 0px;
+	display: inline-block;
+	width: 12px;
+	height: 12px;
+	background-repeat:no-repeat;
+        background-position:center;
+}
 
 span.lineno {
 	padding-right: 4px;
diff --git a/docs/html/dynsections.js b/docs/html/dynsections.js
index 1f4cd14..9b28156 100644
--- a/docs/html/dynsections.js
+++ b/docs/html/dynsections.js
@@ -120,6 +120,75 @@ function toggleInherit(id)
     $(img).attr('src',src.substring(0,src.length-10)+'open.png');
   }
 }
+
+var opened=true;
+// in case HTML_COLORSTYLE is LIGHT or DARK the vars will be replaced, so we write them out explicitly and use double quotes
+var plusImg  = [ "var(--fold-plus-image)",  "var(--fold-plus-image-relpath)" ];
+var minusImg = [ "var(--fold-minus-image)", "var(--fold-minus-image-relpath)" ];
+
+// toggle all folding blocks
+function codefold_toggle_all(relPath) {
+ if (opened) {
+   $('#fold_all').css('background-image',plusImg[relPath]);
+   $('div[id^=foldopen]').hide();
+   $('div[id^=foldclosed]').show();
+ } else {
+   $('#fold_all').css('background-image',minusImg[relPath]);
+   $('div[id^=foldopen]').show();
+   $('div[id^=foldclosed]').hide();
+ }
+ opened=!opened;
+}
+
+// toggle single folding block
+function codefold_toggle(id) {
+  $('#foldopen'+id).toggle();
+  $('#foldclosed'+id).toggle();
+}
+function init_codefold(relPath) {
+  $('span[class=lineno]').css(
+    {'padding-right':'4px',
+     'margin-right':'2px',
+     'display':'inline-block',
+     'width':'54px',
+     'background':'linear-gradient(var(--fold-line-color),var(--fold-line-color)) no-repeat 46px/2px 100%'
+    });
+  // add global toggle to first line
+  $('span[class=lineno]:first').append('<span class="fold" id="fold_all" '+
+                                             'onclick="javascript:codefold_toggle_all('+relPath+');" '+
+                                             'style="background-image:'+minusImg[relPath]+';"></span>');
+  // add vertical lines to other rows
+  $('span[class=lineno]').not(':eq(0)').append('<span class="fold"></span>');
+  // add toggle controls to lines with fold divs
+  $('div[class=foldopen]').each(function() {
+    // extract specific id to use
+    var id    = $(this).attr('id').replace('foldopen','');
+    // extract start and end foldable fragment attributes
+    var start = $(this).attr('data-start');
+    var end   = $(this).attr('data-end');
+    // replace normal fold span with controls for the first line of a foldable fragment
+    $(this).find('span[class=fold]:first').replaceWith('<span class="fold" '+
+                                                       'onclick="javascript:codefold_toggle(\''+id+'\');" '+
+                                                       'style="background-image:'+minusImg[relPath]+';"></span>');
+    // append div for folded (closed) representation
+    $(this).after('<div id="foldclosed'+id+'" class="foldclosed" style="display:none;"></div>');
+    // extract the first line from the "open" section to represent closed content
+    var line = $(this).children().first().clone();
+    // remove any glow that might still be active on the original line
+    $(line).removeClass('glow');
+    if (start) {
+      // if line already ends with a start marker (e.g. trailing {), remove it
+      $(line).html($(line).html().replace(new RegExp('\\s*'+start+'\\s*$','g'),''));
+    }
+    // replace minus with plus symbol
+    $(line).find('span[class=fold]').css('background-image',plusImg[relPath]);
+    // append ellipsis
+    $(line).append(' '+start+'<a href="javascript:codefold_toggle(\''+id+'\')">&#8230;</a>'+end);
+    // insert constructed line into closed div
+    $('#foldclosed'+id).html(line);
+  });
+}
+
 /* @license-end */
 $(document).ready(function() {
   $('.code,.codeRef').each(function() {
diff --git a/docs/html/factorial_8hpp.html b/docs/html/factorial_8hpp.html
index ac9d660..aa2155c 100644
--- a/docs/html/factorial_8hpp.html
+++ b/docs/html/factorial_8hpp.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: factorial.hpp File Reference</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -111,12 +111,12 @@
 <table class="memberdecls">
 <tr class="heading"><td colspan="2"><h2 class="groupheader"><a id="namespaces" name="namespaces"></a>
 Namespaces</h2></td></tr>
-<tr class="memitem:namespacecppbase"><td class="memItemLeft" align="right" valign="top">namespace &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="namespacecppbase.html">cppbase</a></td></tr>
+<tr class="memitem:namespacecppbase" id="r_namespacecppbase"><td class="memItemLeft" align="right" valign="top">namespace &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="namespacecppbase.html">cppbase</a></td></tr>
 <tr class="separator:"><td class="memSeparator" colspan="2">&#160;</td></tr>
 </table><table class="memberdecls">
 <tr class="heading"><td colspan="2"><h2 class="groupheader"><a id="func-members" name="func-members"></a>
 Functions</h2></td></tr>
-<tr class="memitem:a286730dfdeb99c4514f1f51c47b250d0"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">cppbase::computeFactorial</a> (const int integerNumber)</td></tr>
+<tr class="memitem:a286730dfdeb99c4514f1f51c47b250d0" id="r_a286730dfdeb99c4514f1f51c47b250d0"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">cppbase::computeFactorial</a> (const int integerNumber)</td></tr>
 <tr class="memdesc:a286730dfdeb99c4514f1f51c47b250d0"><td class="mdescLeft">&#160;</td><td class="mdescRight">Compute factorial.  <br /></td></tr>
 <tr class="separator:a286730dfdeb99c4514f1f51c47b250d0"><td class="memSeparator" colspan="2">&#160;</td></tr>
 </table>
@@ -126,7 +126,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li><li class="navelem"><a class="el" href="dir_d1bd97ed40e89648596a0852aac26258.html">cppbase</a></li><li class="navelem"><a class="el" href="factorial_8hpp.html">factorial.hpp</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/factorial_8hpp_source.html b/docs/html/factorial_8hpp_source.html
index 66fe15f..e5013b5 100644
--- a/docs/html/factorial_8hpp_source.html
+++ b/docs/html/factorial_8hpp_source.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: factorial.hpp Source File</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -51,6 +51,11 @@
 /* @license-end */
 </script>
 <div id="main-nav"></div>
+<script type="text/javascript">
+/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
+$(document).ready(function() { init_codefold(0); });
+/* @license-end */
+</script>
 </div><!-- top -->
 <div id="side-nav" class="ui-resizable side-nav-resizable">
   <div id="nav-tree">
@@ -101,6 +106,7 @@
 <div class="line"><a id="l00006" name="l00006"></a><span class="lineno">    6</span> </div>
 <div class="line"><a id="l00007" name="l00007"></a><span class="lineno">    7</span><span class="preprocessor">#pragma once</span></div>
 <div class="line"><a id="l00008" name="l00008"></a><span class="lineno">    8</span> </div>
+<div class="foldopen" id="foldopen00009" data-start="{" data-end="}">
 <div class="line"><a id="l00009" name="l00009"></a><span class="lineno"><a class="line" href="namespacecppbase.html">    9</a></span><span class="keyword">namespace </span><a class="code hl_namespace" href="namespacecppbase.html">cppbase</a></div>
 <div class="line"><a id="l00010" name="l00010"></a><span class="lineno">   10</span>{</div>
 <div class="line"><a id="l00011" name="l00011"></a><span class="lineno">   11</span> </div>
@@ -108,6 +114,7 @@
 <div class="line"><a id="l00019" name="l00019"></a><span class="lineno"><a class="line" href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">   19</a></span><span class="keywordtype">int</span> <a class="code hl_function" href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">computeFactorial</a>(<span class="keyword">const</span> <span class="keywordtype">int</span> integerNumber);</div>
 <div class="line"><a id="l00020" name="l00020"></a><span class="lineno">   20</span> </div>
 <div class="line"><a id="l00021" name="l00021"></a><span class="lineno">   21</span>} <span class="comment">// namespace cppbase</span></div>
+</div>
 <div class="ttc" id="anamespacecppbase_html"><div class="ttname"><a href="namespacecppbase.html">cppbase</a></div><div class="ttdef"><b>Definition</b> <a href="factorial_8hpp_source.html#l00009">factorial.hpp:10</a></div></div>
 <div class="ttc" id="anamespacecppbase_html_a286730dfdeb99c4514f1f51c47b250d0"><div class="ttname"><a href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">cppbase::computeFactorial</a></div><div class="ttdeci">int computeFactorial(const int integerNumber)</div><div class="ttdoc">Compute factorial.</div></div>
 </div><!-- fragment --></div><!-- contents -->
@@ -116,7 +123,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="dir_d44c64559bbebec7f509842c48db8b23.html">include</a></li><li class="navelem"><a class="el" href="dir_d1bd97ed40e89648596a0852aac26258.html">cppbase</a></li><li class="navelem"><a class="el" href="factorial_8hpp.html">factorial.hpp</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/files.html b/docs/html/files.html
index c7906c5..50a3079 100644
--- a/docs/html/files.html
+++ b/docs/html/files.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: File List</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -106,7 +106,7 @@
 <!-- start footer part -->
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/graph_legend.html b/docs/html/graph_legend.html
index da8f6ce..4df13ee 100644
--- a/docs/html/graph_legend.html
+++ b/docs/html/graph_legend.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: Graph Legend</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -158,7 +158,7 @@
 <!-- start footer part -->
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/index.html b/docs/html/index.html
index 2d42db5..063a834 100644
--- a/docs/html/index.html
+++ b/docs/html/index.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: cppbase</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -100,7 +100,7 @@
 <!-- start footer part -->
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/minus.svg b/docs/html/minus.svg
new file mode 100644
index 0000000..f70d0c1
--- /dev/null
+++ b/docs/html/minus.svg
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg width="12px" height="12px" viewBox="0 0 105.83333 105.83333" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg">
+  <g>
+    <rect style="fill:#808080;stroke-width:0" width="105.83333" height="105.83334" x="4.2409692e-08" y="-1.2701158e-06" ry="0" />
+    <rect style="fill:#fcfcfc;stroke-width:0" width="79.375" height="79.375" x="13.229166" y="13.229166" />
+    <rect style="fill:#808080;stroke-width:0" width="52.916668" height="15.874998" x="26.458332" y="44.979168" />
+  </g>
+</svg>
diff --git a/docs/html/minusd.svg b/docs/html/minusd.svg
new file mode 100644
index 0000000..5f8e879
--- /dev/null
+++ b/docs/html/minusd.svg
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg width="12px" height="12px" viewBox="0 0 105.83333 105.83333" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg">
+  <g>
+    <rect style="fill:#808080;stroke-width:0" width="105.83333" height="105.83334" x="4.2409692e-08" y="-1.2701158e-06" ry="0" />
+    <rect style="fill:#000000;stroke-width:0" width="79.375" height="79.375" x="13.229166" y="13.229166" />
+    <rect style="fill:#808080;stroke-width:0" width="52.916668" height="15.874998" x="26.458332" y="44.979168" />
+  </g>
+</svg>
diff --git a/docs/html/namespacecppbase.html b/docs/html/namespacecppbase.html
index d8899bd..04753a3 100644
--- a/docs/html/namespacecppbase.html
+++ b/docs/html/namespacecppbase.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: cppbase Namespace Reference</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -98,7 +98,7 @@
 <table class="memberdecls">
 <tr class="heading"><td colspan="2"><h2 class="groupheader"><a id="func-members" name="func-members"></a>
 Functions</h2></td></tr>
-<tr class="memitem:a286730dfdeb99c4514f1f51c47b250d0"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">computeFactorial</a> (const int integerNumber)</td></tr>
+<tr class="memitem:a286730dfdeb99c4514f1f51c47b250d0" id="r_a286730dfdeb99c4514f1f51c47b250d0"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0">computeFactorial</a> (const int integerNumber)</td></tr>
 <tr class="memdesc:a286730dfdeb99c4514f1f51c47b250d0"><td class="mdescLeft">&#160;</td><td class="mdescRight">Compute factorial.  <br /></td></tr>
 <tr class="separator:a286730dfdeb99c4514f1f51c47b250d0"><td class="memSeparator" colspan="2">&#160;</td></tr>
 </table>
@@ -135,7 +135,7 @@ <h2 class="memtitle"><span class="permalink"><a href="#a286730dfdeb99c4514f1f51c
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     <li class="navelem"><a class="el" href="namespacecppbase.html">cppbase</a></li>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/namespacemembers.html b/docs/html/namespacemembers.html
index 09bea93..6187849 100644
--- a/docs/html/namespacemembers.html
+++ b/docs/html/namespacemembers.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: Namespace Members</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -98,7 +98,7 @@
 <!-- start footer part -->
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/namespacemembers_func.html b/docs/html/namespacemembers_func.html
index 73559a5..76a7a3c 100644
--- a/docs/html/namespacemembers_func.html
+++ b/docs/html/namespacemembers_func.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: Namespace Members</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -98,7 +98,7 @@
 <!-- start footer part -->
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/namespaces.html b/docs/html/namespaces.html
index 401738c..08567af 100644
--- a/docs/html/namespaces.html
+++ b/docs/html/namespaces.html
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
-<meta name="generator" content="Doxygen 1.9.7"/>
+<meta name="generator" content="Doxygen 1.9.8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <title>cppbase: Namespace List</title>
 <link href="tabs.css" rel="stylesheet" type="text/css"/>
@@ -34,7 +34,7 @@
 </table>
 </div>
 <!-- end header part -->
-<!-- Generated by Doxygen 1.9.7 -->
+<!-- Generated by Doxygen 1.9.8 -->
 <script type="text/javascript">
 /* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
 var searchBox = new SearchBox("searchBox", "search/",'.html');
@@ -103,7 +103,7 @@
 <!-- start footer part -->
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
-    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.7 </li>
+    <li class="footer">Generated by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
   </ul>
 </div>
 </body>
diff --git a/docs/html/navtree.css b/docs/html/navtree.css
index c8a7766..69211d4 100644
--- a/docs/html/navtree.css
+++ b/docs/html/navtree.css
@@ -42,7 +42,6 @@
   text-decoration:none;
   padding:0px;
   margin:0px;
-  outline:none;
 }
 
 #nav-tree .label {
diff --git a/docs/html/navtree.js b/docs/html/navtree.js
index f23e984..93dd3d4 100644
--- a/docs/html/navtree.js
+++ b/docs/html/navtree.js
@@ -94,7 +94,7 @@ function cachedLink()
   }
 }
 
-function getScript(scriptName,func,show)
+function getScript(scriptName,func)
 {
   var head = document.getElementsByTagName("head")[0];
   var script = document.createElement('script');
@@ -124,7 +124,7 @@ function createIndent(o,domNode,node,level)
         node.plus_img.innerHTML=arrowRight;
         node.expanded = false;
       } else {
-        expandNode(o, node, false, false);
+        expandNode(o, node, false, true);
       }
     }
     node.expandToggle.appendChild(imgNode);
@@ -265,15 +265,15 @@ function showRoot()
   })();
 }
 
-function expandNode(o, node, imm, showRoot)
+function expandNode(o, node, imm, setFocus)
 {
   if (node.childrenData && !node.expanded) {
     if (typeof(node.childrenData)==='string') {
       var varName    = node.childrenData;
       getScript(node.relpath+varName,function(){
         node.childrenData = getData(varName);
-        expandNode(o, node, imm, showRoot);
-      }, showRoot);
+        expandNode(o, node, imm, setFocus);
+      });
     } else {
       if (!node.childrenVisited) {
         getNode(o, node);
@@ -281,6 +281,9 @@ function expandNode(o, node, imm, showRoot)
       $(node.getChildrenUL()).slideDown("fast");
       node.plus_img.innerHTML = arrowDown;
       node.expanded = true;
+      if (setFocus) {
+        $(node.expandToggle).focus();
+      }
     }
   }
 }
@@ -344,7 +347,7 @@ function showNode(o, node, index, hash)
       getScript(node.relpath+varName,function(){
         node.childrenData = getData(varName);
         showNode(o,node,index,hash);
-      },true);
+      });
     } else {
       if (!node.childrenVisited) {
         getNode(o, node);
@@ -362,11 +365,11 @@ function showNode(o, node, index, hash)
             n.childrenData = getData(varName);
             node.expanded=false;
             showNode(o,node,index,hash); // retry with child node expanded
-          },true);
+          });
         } else {
           var rootBase = stripPath(o.toroot.replace(/\..+$/, ''));
           if (rootBase=="index" || rootBase=="pages" || rootBase=="search") {
-            expandNode(o, n, true, true);
+            expandNode(o, n, true, false);
           }
           selectAndHighlight(hash,n);
         }
@@ -444,7 +447,7 @@ function navTo(o,root,hash,relpath)
       if (navTreeSubIndices[i]) {
         gotoNode(o,i,root,hash,relpath);
       }
-    },true);
+    });
   }
 }
 
diff --git a/docs/html/plus.svg b/docs/html/plus.svg
new file mode 100644
index 0000000..0752016
--- /dev/null
+++ b/docs/html/plus.svg
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg width="12px" height="12px" viewBox="0 0 105.83333 105.83333" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg">
+  <g>
+    <rect style="fill:#808080;stroke-width:0" width="105.83333" height="105.83334" x="4.2409692e-08" y="-1.2701158e-06" ry="0" />
+    <rect style="fill:#fcfcfc;stroke-width:0" width="79.375" height="79.375" x="13.229166" y="13.229166" />
+    <rect style="fill:#808080;stroke-width:0" width="52.916668" height="15.874998" x="26.458332" y="44.979168" />
+    <rect style="fill:#808080;stroke-width:0" width="15.874998" height="52.916668" x="44.979168" y="26.458332" />
+  </g>
+</svg>
diff --git a/docs/html/plusd.svg b/docs/html/plusd.svg
new file mode 100644
index 0000000..0c65bfe
--- /dev/null
+++ b/docs/html/plusd.svg
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg width="12px" height="12px" viewBox="0 0 105.83333 105.83333" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg">
+  <g>
+    <rect style="fill:#808080;stroke-width:0" width="105.83333" height="105.83334" x="4.2409692e-08" y="-1.2701158e-06" ry="0" />
+    <rect style="fill:#000000;stroke-width:0" width="79.375" height="79.375" x="13.229166" y="13.229166" />
+    <rect style="fill:#808080;stroke-width:0" width="52.916668" height="15.874998" x="26.458332" y="44.979168" />
+    <rect style="fill:#808080;stroke-width:0" width="15.874998" height="52.916668" x="44.979168" y="26.458332" />
+  </g>
+</svg>
diff --git a/docs/html/search/all_0.js b/docs/html/search/all_0.js
index b77c8dd..6d6b5b0 100644
--- a/docs/html/search/all_0.js
+++ b/docs/html/search/all_0.js
@@ -1,6 +1,6 @@
 var searchData=
 [
   ['computefactorial_0',['computeFactorial',['../namespacecppbase.html#a286730dfdeb99c4514f1f51c47b250d0',1,'cppbase']]],
-  ['cppbase_1',['cppbase',['../namespacecppbase.html',1,'cppbase'],['../index.html',1,'(Global Namespace)']]],
+  ['cppbase_1',['cppbase',['../namespacecppbase.html',1,'cppbase'],['../index.html',1,'cppbase']]],
   ['cppbaseall_2ehpp_2',['cppbaseAll.hpp',['../cppbaseAll_8hpp.html',1,'']]]
 ];
diff --git a/docs/html/search/search.js b/docs/html/search/search.js
index 9b7a52a..6fd40c6 100644
--- a/docs/html/search/search.js
+++ b/docs/html/search/search.js
@@ -195,6 +195,7 @@ function SearchBox(name, resultsPath, extension)
     }
     else if (e.keyCode==27) // Escape out of the search field
     {
+      e.stopPropagation();
       this.DOMSearchField().blur();
       this.DOMPopupSearchResultsWindow().style.display = 'none';
       this.DOMSearchClose().style.display = 'none';
@@ -289,6 +290,7 @@ function SearchBox(name, resultsPath, extension)
     }
     else if (e.keyCode==13 || e.keyCode==27)
     {
+      e.stopPropagation();
       this.OnSelectItem(this.searchIndex);
       this.CloseSelectionWindow();
       this.DOMSearchField().focus();
@@ -670,6 +672,7 @@ function SearchResults(name)
       }
       else if (this.lastKey==27) // Escape
       {
+        e.stopPropagation();
         searchBox.CloseResultsWindow();
         document.getElementById("MSearchField").focus();
       }
@@ -713,6 +716,7 @@ function SearchResults(name)
       }
       else if (this.lastKey==27) // Escape
       {
+        e.stopPropagation();
         searchBox.CloseResultsWindow();
         document.getElementById("MSearchField").focus();
       }
@@ -806,6 +810,7 @@ function createResults(resultsPath)
 function init_search()
 {
   var results = document.getElementById("MSearchSelectWindow");
+  results.tabIndex=0;
   for (var key in indexSectionLabels)
   {
     var link = document.createElement('a');
@@ -816,5 +821,20 @@ function init_search()
     results.appendChild(link);
   }
   searchBox.OnSelectItem(0);
+
+  var input = document.getElementById("MSearchSelect");
+  var searchSelectWindow = document.getElementById("MSearchSelectWindow");
+  input.tabIndex=0;
+  input.addEventListener("keydown", function(event) {
+    if (event.keyCode==13 || event.keyCode==40) {
+      event.preventDefault();
+      if (searchSelectWindow.style.display == 'block') {
+        searchBox.CloseSelectionWindow();
+      } else {
+        searchBox.OnSearchSelectShow();
+        searchBox.DOMSearchSelectWindow().focus();
+      }
+    }
+  });
 }
 /* @license-end */
