Formbuilder + Focus Property

It’s possible to use focus property when using FormBuilder?


$config = array(

            'layout' => TbHtml::FORM_LAYOUT_HORIZONTAL,

            

            'elements' => array(

                'anode' => array(

                    'type' => TbHtml::INPUT_TYPE_TEXT,

                ),

                'anoate' => array(

                    'type' => TbHtml::INPUT_TYPE_TEXT,

                ),

                

            ),

            'buttons' => array(

                'submit' => array(

                    'type' => TbHtml::BUTTON_TYPE_SUBMIT,

                    'label' => 'OK',

                    'name' => 'submit',

                    'attributes' => array('color' => TbHtml::BUTTON_COLOR_PRIMARY),

                ),                               

            ),

            'focus'=>'input:text[value=""]:first' ,

);

not working… but works w/o formbuild.

Regards,