MySql query not being executed

I have recently downloaded and modified a IPN listener, and I want it to do something more than log the donation, but to add points to a user. However it doesn't do anything even though I am sure my code is correct. The first Mysql_Query works and logs the donation but the second one doesnt. I need help, please!

    //require paypal, connection and config

    $p = new paypal_class;
    $p->paypal_url = $payPalURL;

    if ($p->validate_ipn()) 
    {
        if($p->ipn_data['payment_status']=='Completed')
        {
            $amount = $p->ipn_data['mc_gross'] - $p->ipn_data['mc_fee'];

            mysql_query("INSERT INTO dc_donations( transaction_id, donor_email, amount, original_request)
                         VALUES (
                                 '".esc($p->ipn_data['txn_id'])."',
                                 '".esc($p->ipn_data['payer_email'])."',
                                  ".(float)$amount.",
                                 '".esc(http_build_query($_POST))."'
                                 )");
            mysql_query("INSERT INTO dc_credits (SteamID,Credits) 
                         VALUES ('TEST','1000')");
        }
    }

    function esc($str)
    {
        global $link;
        return mysql_rea开发者_Python百科l_escape_string($str,$link);
    }

btw, If you need further code than I will add it

You can try putting the 2nd mysql_query first so that it gets executed first and if there is error, you can see the error without inserting to the other table.