wwwroot.'/enrol/ipay/ipn.php';
$cst ='0';
$crl ='0';
$hshkey = "demo";//and change this to required security key
$p1 =$USER->id;
$p2=$course->id;
$p3=$instance->id;
$p4='';$crl='0';$cur =$curr;
$datastring = $live.$mm.$mb.$dc.$cc.$mer.$oid.$inv.$ttl.$userphonenumber.$useremail.$vid.$cur.$p1.$p2.$p3.$p4.$cbk.$cst.$crl;
$hashkey = hash_hmac('sha1', $datastring, $hshkey);
?>