final Form schemaForm = new Form("form");
schemaForm.setModel(new CompoundPropertyModel(schema));
final AjaxTextFieldPanel name = new AjaxTextFieldPanel("name", getString("name"), new PropertyModel<String>(
schema, "name"));
name.addRequiredLabel();
final AjaxTextFieldPanel expression = new AjaxTextFieldPanel("expression", getString("expression"),
new PropertyModel<String>(schema, "expression"));
expression.addRequiredLabel();
name.setEnabled(createFlag);
final IndicatingAjaxButton submit = new IndicatingAjaxButton("apply", new ResourceModel("submit")) {