function hidden_columns($result)
 {
     global $frm_cols;
     $form_id = FrmProAppHelper::get_current_form_id();
     $return = false;
     foreach ((array) $result as $r) {
         if (!empty($r)) {
             $form_prefix = explode('_', $r);
             $form_prefix = $form_prefix[0];
             if ((int) $form_prefix == (int) $form_id) {
                 $return = true;
                 break;
             }
             unset($form_prefix);
         }
     }
     if ($return) {
         return $result;
     }
     $i = count($frm_cols);
     $max_columns = 8;
     if ($i > $max_columns) {
         global $frm_current_form;
         if ($frm_current_form) {
             $frm_current_form->options = maybe_unserialize($frm_current_form->options);
         }
         if ($frm_current_form and isset($frm_current_form->options['hidden_cols']) and !empty($frm_current_form->options['hidden_cols'])) {
             $result = $frm_current_form->options['hidden_cols'];
         } else {
             $cols = $frm_cols;
             $cols = array_reverse($cols, true);
             $result[] = $form_id . '_id';
             $i--;
             $result[] = $form_id . '_item_key';
             $i--;
             foreach ($cols as $col_key => $col) {
                 if ($i > $max_columns) {
                     $result[] = $col_key;
                 }
                 //remove some columns by default
                 $i--;
             }
         }
     }
     return $result;
 }