private Button buildRemoveParameterButton(final HorizontalPanel entry) {
   Button remButton = new Button();
   remButton.setStyleName(removeParamButton.getStyleName());
   remButton.setHTML(removeParamButton.getHTML());
   remButton.addClickHandler(
       new ClickHandler() {
         public void onClick(ClickEvent event) {
           removeParameter(entry);
           enableSaveButton();
         }
       });
   return remButton;
 }
 @UiHandler("addParamButton")
 void onAddParamClicked(ClickEvent event) {
   addParameter("", "");
   addParamButton.setFocus(true);
   enableSaveButton();
 }
 private void disableDeleteButton() {
   deleteButton.setEnabled(false);
 }
 private void enableDeleteButton() {
   deleteButton.setEnabled(true);
 }
 private void disableSaveButton() {
   saveButton.setEnabled(false);
 }
 private void enableSaveButton() {
   if (!isConfigListEmpty()) saveButton.setEnabled(true);
 }