help me make a relation between 2 tables (php sql)

Im working on getting paypal payments into my website. I have [login to view URL] from before and now payments.db. In [login to view URL] i have a 'userId' and in [login to view URL] a 'id' in my [login to view URL] i call [login to view URL] and have this code: // PAYMENT VALIDATED & VERIFIED! if($valid_txnid && $valid_price){ $orderid = updatePayments($data); if($orderid){ // Payment has been made & successfully inserted into the Database }else{ // Error inserting into DB // E-mail admin or alert user in [login to view URL] i have this code: function updatePayments($data){ global $link; if(is_array($data)){ $sql = mysql_query("INSERT INTO `payments` (txnid, payment_amount, payment_status, itemid, createdtime) VALUES ( '".$data['txn_id']."' , '".$data['payment_amount']."' , '".$data['payment_status']."' , '".$data['item_number']."' , '".date("Y-m-d H:i:s")."' )", $link); return mysql_insert_id($link); } } What i need is the solution for this: in my [login to view URL] update two cells with the value of item_number and date from [login to view URL] i need the userId from [login to view URL] to be the id inserted into [login to view URL] so i can connect these two tables when i get the values from both. i need this asap - like the next hour and i want the code to be sent on chat. i can upload files etc