contentPanel.add(descriptionLabel);
contentPanel.add(button);
horizontalPanel.add(contentPanel);
// center the horizontal panel within the popup
CenterPanel mainPanel = new CenterPanel(horizontalPanel);
mainPanel.setStylePrimaryName(RESOURCES.styles().mainPanel());
setWidget(((MyUiBinder)GWT.create(MyUiBinder.class)).createAndBindUi(this));
content_.setWidget(mainPanel);
}