$form->radio ("sex","sex")->options (['m' => 'Female', 'f'=> 'Male'])->default ('m')->disableHorizontal ();
        $script = <<<EOT
        $("input:radio [name='sex']").on ('ifChecked', function (event){console.log ("radio change,val:" +  $(this).val ());

    });
EOT;
        \Admin::script ($script);