new Model<String>(_b));
final DropDownChoice<String> c = new DropDownChoice<String>("c",
new Model<String>("2"), Arrays.asList(new String[] { "1", "2",
"3" }));
c.add(new StatelessAjaxFormComponentUpdatingBehavior("change") {
@Override
protected PageParameters getPageParameters() {
return new PageParameters();
}