mysql_fetch_array将值拉入变量

I know that this is dozy, but getting to the end of my tether, this should work, but I can't see why I can't place the first value of my order table into the variable order_id, can anyone see my mistake?

Thanks

$con = mysql_connect("localhost", "tim", "password");

if (!$con) {
    die('Could not connect: '.mysql_error());
}

$sql = "SELECT TOP 1 order_order_id FROM tbl_order ORDER BY order_id DESC";
$result = mysql_query($sql, $con);

while ($rows = mysql_fetch_array($result)) {
    $order_id = $rows;
}

Use this code and let me know if it works:

$con = mysql_connect("localhost","tim","password");

if (!$con)
   {
   die('Could not connect: ' . mysql_error());
  }
$sql = "SELECT TOP 1 order_order_id FROM tbl_order ORDER BY order_id DESC";
$result = mysql_query($sql,$con);
if (mysql_num_rows($result)) {
     $rows = mysql_fetch_assoc($result);    
     $order_id = $rows['order_order_id'];    
} else {
     die('No order ID found');
}