Eclipse Editor highlight syntax errors

Question

just implemented a custom editor with syntax checker etc. The creation of markers working well on saving editor and are displayed in the problem view. But how to underline the error in the editor. What I missed?

Now:

Should be:

<extension
         point="org.eclipse.ui.editors.markerAnnotationSpecification">
         <specification
            icon = "icons/fail.gif"
            annotationType="com.customeditor"
            verticalRulerPreferenceKey="highlight.rulers.vertical"
            textPreferenceKey="highlight.text"
            colorPreferenceKey="highlight.color"
            highlightPreferenceKey="highlight.background"
            textPreferenceValue="true"
            textStylePreferenceValue="PROBLEM_UNDERLINE"
            overviewRulerPreferenceKey="highlight.rulers.overview"
            presentationLayer="4"
            highlightPreferenceValue="true"
            label="DiffSiteB"
            symbolicIcon="error"
            colorPreferenceValue="255,0,0"
            verticalRulerPreferenceValue="true"
            overviewRulerPreferenceValue="true"
            textStylePreferenceKey="highlight.text.style" >
        </specification >
    </extension>

public IMarker createMarker(IResource res, String location, String message, int start, int end) throws CoreException {
  IMarker marker = null;

  if (res != null) {
     marker = res.createMarker("com.customedtior");
     marker.setAttribute(IMarker.SEVERITY, IMarker.SEVERITY_ERROR);
     marker.setAttribute(IMarker.CHAR_START, start);
     marker.setAttribute(IMarker.CHAR_END, end);
     marker.setAttribute(IMarker.LOCATION, location);
     marker.setAttribute(IMarker.MESSAGE, message);
         
     SimpleMarkerAnnotation ann = new SimpleMarkerAnnotation(marker);
     ann.setType(JavaMarkerAnnotation.ERROR_ANNOTATION_TYPE);
     getVerticalRuler().getModel().addAnnotation(ann, new Position(start, end));
     getVerticalRuler().update();
  }
  return marker;
}