I've created a Dialog using GXT, but I don't know how to remove the OK button.

My code for creating the dialog:

```
Dialog dialog = new Dialog();
dialog.setHeadingText("My group invites");
dialog.setPixelSize(100, 100);
dialog.setHideOnButtonClick(true);
dialog.addButton(new TextButton("TEST", new SelectHandler(){

    @Override
    public void onSelect(SelectEvent event) {
          // TODO Auto-generated method stub

    }

}));

```

Result: ![enter image description here](https://i.stack.imgur.com/n8lZc.png)

Anybody knows how to get rid of the OK button?

I'm using Sencha GXT 3.1.0 beta