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        $session =& CRM_Core_Session::singleton( );
            $contactID = $session->get( 'userID' );
            $id = CRM_Utils_Request::retrieve( 'id', 'Positive', $this, false, $userID );
        //get the userChecksum and contact id
        $userChecksum = CRM_Utils_Request::retrieve( 'cs', 'String', $this );
        $linkID    = CRM_Utils_Request::retrieve( 'cid', 'Positive', $this );

        $validUser = false;
        if ( $contactID ) {
            //check for authenticated  user.
            $validUser = true;
        } else if ( $userChecksum ) {
            //check for anonymous user.
            require_once 'CRM/Contact/BAO/Contact/Utils.php';
            $validUser = CRM_Contact_BAO_Contact_Utils::validChecksum( $linkID, $userChecksum );

            //make sure cid is same as pledge contact id
            $contactID = $linkID;
        }