private boolean performDoctypeOk() {
   int index = fDocumentTypeCombo.getSelectionIndex();
   if (index > -1) {
     String id = (String) fDocumentTypeIds.get(index);
     if (id == null || id.equalsIgnoreCase(SELECT_NONE)) {
       // if none, use null
       id = null;
     }
     try {
       HTMLContentProperties.setProperty(HTMLContentProperties.DOCUMENT_TYPE, getResource(), id);
     } catch (CoreException e) {
       // maybe in future, let user know there was a problem saving
       // file
       Logger.log(Logger.WARNING_DEBUG, e.getMessage(), e);
       return false;
     }
   }
   return true;
 }
  private void initializeDoctypeValues() {
    int index = 0;
    String doctype =
        HTMLContentProperties.getProperty(
            HTMLContentProperties.DOCUMENT_TYPE, getResource(), false);
    if (doctype != null) {
      /*
       * If item is already part of combo, select it. Otherwise, select
       * none.
       */
      index = fDocumentTypeIds.indexOf(doctype);
    }

    // set combobox
    index = index >= 0 ? index : 0;
    fDocumentTypeCombo.select(index);

    updateDoctypeText(index, doctype);
  }