function IsValidAgenyShortName($shortname)
 {
     if (is_string($shortname) == False) {
         return False;
     }
     if (strlen($shortname) != 4) {
         return False;
     }
     $agencyManager = new AgencyManager();
     $valid = $agencyManager->ValidAgencyByShortName($shortname);
     return $valid;
 }