PHP MySql Update Where problem

[James Smith]

Hi I can't work out why this is not working. It works in a separate table or if I don't do Update Where, just Insert into, so that it works on a new row but does will not update the row I want.

Any help would be very appreicated.

php Code:
function updatePayments($data){
global $link;
if(is_array($data)){
$sql = mysql_query("UPDATE `gigs` SET (txnid, payment_amount, payment_status, itemid, createdtime)
VALUES ('".$data['txn_id']."' , '".$data['payment_amount']."' , '".$data['payment_status']."' , '".$data['item_number']."' , '".date("Y-m-d H:i:s")."')
WHERE`gigname` ='".$data['item_number']."'", $link);
return mysql_insert_id($link);
}
}