public static function maybe_load_css($form, $this_load, $global_load)
 {
     $load_css = FrmForm::is_form_loaded($form, $this_load, $global_load);
     if ($load_css) {
         global $frm_vars;
         self::footer_js('header');
         $frm_vars['css_loaded'] = true;
     }
 }