public Object execute(ExecutionEvent event) throws ExecutionException {
        //get some context information:
        //1. what file are we displaying
        //2. what position is the cursor at
        ITextEditor editor = (ITextEditor) HandlerUtil.getActiveEditorChecked(event);
        IEditorInput input = editor.getEditorInput();
        IFile file = ((FileEditorInput) input).getFile();
        ICompilationUnit cu = JavaCore.createCompilationUnitFrom(file);
        TextSelection selection = (TextSelection) editor.getSelectionProvider().getSelection();
        int cursorOffset = selection.getOffset();

        //display the dialog
        MyDialog dialog = new MyDialog(getShell(event));
        int res = dialog.open();
        if (res==0) {
            String theText = dialog.getTheTextToInsert();
            try {
                //add the code section as text at the cursor
                TextEdit edit = new InsertEdit(cursorOffset, theText);   
                cu.applyTextEdit(edit, null);                    

            } catch (JavaModelException e) {                    
                throw new ExecutionException(e.getMessage());
            }
        }
    }

    protected Shell getShell(ExecutionEvent event) {
        return HandlerUtil.getActiveShell(event);
    }