Set focus on a component with Apache Wicket?

Once you create your behavior to set the focus, you should be able to add it to the component on any event, just make sure that component is part of the AjaxRequestTarget. I don't see why this wouldn't work...

myRadioButton.add(new AjaxEventBehavior("onchange") {
 @Override
 protected void onEvent(AjaxRequestTarget target) {
    myOtherComponent.add(new DefaultFocusBehavior());
        target.addComponent(myForm);
 }
});

Here's a link that shows how to create the default focus behavior if you do not have one already: http://javathoughts.capesugarbird.com/2009/01/wicket-and-default-focus-behavior.html