Inside a class IOS_Controller_Action_Helper_PatientIdCheck extends Zend_Controller_Action_Helper_Abstract

....

      $fm = $this->getActionController()->getHelper('FlashMessenger');
      $fm->flashMessenger(array('error ui-state-error ui-corner-all'=>'No patient Id was specified.'));


.....

My View Helper starts like..
class IOS_View_Helper_FlashMessenger extends Zend_View_Helper_Abstract...


The error I get

Fatal error: Call to undefined method Zend_Controller_Action_Helper_FlashMessenger::flashMessenger() in ...Controller/Action/Helper/PatientIdCheck.php on line 25