Merge pull request #1314 from pradpnayak/CRM-13004

-- fixed notice error for CRM-13004

CRM/Event/Form/Registration/Confirm.php

@@ -982,7 +982,7 @@ class CRM_Event_Form_Registration_Confirm extends CRM_Event_Form_Registration {
     // create contribution record
     $contribution = CRM_Contribute_BAO_Contribution::add($contribParams, $ids);
     // CRM-11124
-    CRM_Event_BAO_Participant::createDiscountTrxn($form->_eventId, $contribParams, $params['amount_priceset_level_radio']);
+    CRM_Event_BAO_Participant::createDiscountTrxn($form->_eventId, $contribParams, CRM_Utils_Array::value('amount_priceset_level_radio', $params, NULL));
 
     // process soft credit / pcp pages
     CRM_Contribute_Form_Contribution_Confirm::processPcpSoft($params, $contribution);