Button okButton = new Button(GuiFactory.strings.ok());
okButton.addClickListener(new ClickListener() {
public void onClick(Widget sender) {
GuiFactory.blockScreen(false);
dialogBox.hide();
}
});
aboutPanel.add(new HTML("<br />"));
aboutPanel.add(okButton);
aboutPanel.setCellHorizontalAlignment(okButton, HasHorizontalAlignment.ALIGN_CENTER);