disable/enable toolbar button in runtime

title="something"

editor.contextMenu.addListener(function(element)
{
  if (element) 
    element = element.getAscendant('a', true);
  if (element && !element.isReadOnly() && !element.data('cke-realelement') && element.getAttribute("title") != '')
    return { inlinepageItem : CKEDITOR.TRISTATE_OFF };
  return null;
});