/**
  * Add additional data to form element
  *
  * @param Varien_Data_Form_Element_Abstract $element
  * @return Mage_Adminhtml_Block_Sales_Order_Create_Form_Abstract
  */
 protected function _addAdditionalFormElementData(Varien_Data_Form_Element_Abstract $element)
 {
     if ($element->getId() == 'region_id') {
         $element->setNoDisplay(true);
     }
     return $this;
 }