add.addSelectionListener( new SelectionAdapter() {
// Add an item, should pop up the editor
public void widgetSelected(SelectionEvent e) {
DSLMappingEntry newItem = new AntlrDSLMappingEntry();
MappingEditor editor = new MappingEditor( getSite().getShell() );//shell);
editor.create();
editor.getShell().setText( "New language mapping" );
editor.setTitle( "Create a new language element mapping." );