update cart

[ggalan]

i have a cart with multiple items that has a numeric input field and would like to update the dB according to that field, this is what i have so far.
my problem is how do i update the cart with that input field and write into the dB?

$id = $_GET['id'];
$queryX = "SELECT * FROM trackcarts INNER JOIN products ON products.productID = trackcarts.productID WHERE sessionID='$cartid' AND deleted ='0'";
$resultX = mysql_query($queryX) or die (mysql_error());


<?
$count = 0;
while ($rowX = mysql_fetch_array($resultX)) {
    echo "<tr>\n";
    echo "<td height='60' width='80' style='padding-bottom:30px;'>\n<a href='product.php?id=";
    print_r ($rowX['productID']);
    echo"&view=A '><img class='barImg' src='assets/main_small/A_";
    print_r ($rowX['productID']);
    echo ".jpg' width='50' height='50' /></a>\n</td>\n";
    
    echo "<td valign='bottom' width='200' style='padding-bottom:30px;' '>\n";
    echo"<ul class='cartDescription'>\n<li class='cartDescript1'>";
    print_r ($rowX['itemName']);
    echo "</li>\n<li class='cartDescript2'>";
    
    $str6 = ($rowX['productID']);
    echo substr($str6, 0, 6);
    
    echo"</li>\n</ul>\n";
    echo "</td>\n";
    
    echo "<td valign='bottom' width='200' style='padding-bottom:30px;' '>\n";
    echo"<ul class='cartDescription'>\n<li class='cartDescript1'>";
    print_r ($rowX['fabricName']);
    echo "</li>\n<li class='cartDescript2'>";
    
    $str3 = ($rowX['productID']);
    $three = substr($str3, 0, 3);
    if ($three == "VOY") {
        $str3 = ($rowX['productID']);
        echo substr($str3, -3);
    }else {
        $str3 = ($rowX['productID']);
        echo substr($str3, -2);
    }
    
    echo"</li>\n</ul>\n";
    echo "</td>\n";
    
    echo "<td valign='bottom' width='100' style='padding-bottom:30px;' '>\n";
    //print_r ($rowX['qty']);
    echo "<form><input type='text' name='qty' size= '5' value='";
    $qty = ($rowX['qty']);
    echo $qty;
    echo "' /></form>";
    echo "</td>\n";
    
    echo "<td valign='bottom' width='120' style='padding-bottom:30px;' '>\n";
     $price =  ($rowX['price']);
    echo $price/2;
    echo "</td>\n";
    
    echo "<td align='left' valign='bottom' width='120' style='padding-bottom:30px;'><a class='itemNum' href='cartRemove.php?id=";
    print_r ($rowX['productID']);
    echo "'>remove</a></td>\n";
    echo "<td align='right' valign='bottom' width='120' style='padding-bottom:30px;' width='50'>";
    echo "<a href='cartupdate.php?id=";  //////<<<<< code below
    print_r ($rowX['productID']);
    echo "&qty=";
    echo $_GET["qty"];
    echo"'>update cart</a>";
    echo "</td>\n</tr>\n";
    $count++;
}
echo"</table>";
?>

then cartupdate.php lookslike this. i will have multiple items so i know that the variable $qty will prob. not work

<?php
session_start();
if (!empty($cartid)) {
    $cartid = $_SESSION['cartid'];
} else {
    $cartid = session_id();
    $_SESSION['cartid'] = $cartid;
    $visitor = $_SERVER[REMOTE_ADDR];
}
include("dbconnect.php");

$id = $_GET['id'];
$qty = $_GET['qty'];

$queryD = "UPDATE trackcarts SET qty = $qty WHERE sessionID = '$cartid' AND productID='$id'";

$resultD = mysql_query($queryD) or die (mysql_error());

include("cart.php");
exit();
?>