Headmodel: clarify error for NIRS (#631)

* Clarify error for NIRS
* Update error message

toolbox/forward/panel_headmodel.m

@@ -329,10 +329,14 @@ function UpdateComment(varargin)
  isEeg = any(strcmpi(sStudies(i).Channel.DisplayableSensorTypes, 'EEG'));
  isEcog = any(strcmpi(sStudies(i).Channel.DisplayableSensorTypes, 'ECOG'));
  isSeeg = any(strcmpi(sStudies(i).Channel.DisplayableSensorTypes, 'SEEG'));
+ isNIRS = any(strcmpi(sStudies(i).Channel.DisplayableSensorTypes, 'NIRS'));
  end
  end
  % Check that at least one modality is available
- if ~isMeg && ~isEeg && ~isEcog && ~isSeeg
+ if isNIRS
+ errMessage = ['To compute head model for NIRS, use process:' 10 'NIRS > Sources > Compute head model from fluence' 10 'NIRSTORM plugin is required'];
+ return;
+ elseif ~isMeg && ~isEeg && ~isEcog && ~isSeeg
  errMessage = 'No valid sensor types to estimate a head model.';
  return;
  end