/**
  * Get the forms ids for joining as the named child form's id with the parent  of the named parent form
  * @param string $childFormName the name of the child form in the relationship
  * @param I2CE_Form $parentFormObj
  * @param array $joinData The array containg the join data
  * @param array $where
  * @param array $limit
  * @return mixed. An array of form ids
  */
 public function getFormIdsJoiningOn_parent($childFormName, $parentFormObj, $joinData, $where, $limit)
 {
     $form = $this->getForm($childFormName);
     if ($form != $parentFormObj->getParentForm()) {
         return array();
     }
     $ids = I2CE_FormStorage::search($form, false, $where, array());
     if (is_string($ids)) {
         $ids = array($ids);
     }
     $id = $parentFormObj->getParentId();
     if (is_array($ids) && in_array($id, $ids)) {
         return array($id);
     } else {
         return array();
     }
     //return " JOIN $refChildForm AS `$childFormName`  ON `$childFormName`.id = `parent_form`.parent ";
 }