<?php

function GetLicense($userid, $product)
{
$server = 'localhost';
$username = 'username';
$password = 'password';
$database = 'databaseName';

    $con = mysql_connect($server,$username,$password);
    mysql_select_db($database, $con);

    /*
    First check to see if the user has a license already
    */

    $command = "SELECT license FROM test WHERE userid=$userid and product='$product' limit 1";
    $result = mysql_query($command);

    if(mysql_num_rows($result) == 0)
    {
        /*
        Next check if there are any licenses available
        */
        $command2 = "SELECT license FROM test WHERE userid IS NULL AND product='$product' limit 1";
        $result = mysql_query($command2);
        if(mysql_num_rows($result) > 0)
        {
            /*
            set an unassigned code
            */
            $command1 = "UPDATE test SET userid = $userid WHERE license  =(SELECT license FROM (select license from test WHERE userid IS NULL AND product='$product' limit 1) AS temp)";
            $result = mysql_query($command1);
        }
        else
        {
            return "No License's available for this product.";
        }
    }
    /*
    Return code
    */
    $result = mysql_query($command);
    return mysql_result($result,0);

}
/*
    below is for sample make sure you sanatize the inputs so users cant fiddle with it
*/
echo GetLicense($_GET['u'], 'WS');
?>