类似网易的验证 -JQuery.html

<!DOCTYPE html>
<html lang="zh">
<head>
	<meta charset="UTF-8" />
	<title>Document</title>
<style type="text/css">
.red{
	border: 1px solid red;
}	
.green{
	border: 1px solid green;
}
</style>
</head>
<body>
	用户名：<input type="text" id="user"/><span id="span"></span>
<script src="jquery-3.2.1.min.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
	$('#user').blur(function(){ 
		$.ajax({
			url: "php/get_json.php",
			data: {
				user:$('#user').val()
			},
			dataType: "json",
			success: function (data) {
				$('#span').text(data.msg);
			}
		});
	});
</script>
</body>
</html>