Need help with image upload

Hi
Im trying to upload and update the image after uploading to the database... but i can only be able to upload the image and am not able to update the image... can anyone help me out with this ... the full code is pasted below:

<?
include("../application.php");
require_login();
require_priv("admin");
include("template/header.php");
switch (nvl($mode)) {
case "add" :
print_add_product_form(nvl($category_id, 0));
break;
case "edit" :
print_edit_product_form($id);
break;
case "del" :
delete_product($id);
print_product_list();
break;
case "insert" :
insert_product($id, $_POST, $HTTP_POST_FILES);
print_product_list();
break;
case "update" :
update_product($id, $_POST, $HTTP_POST_FILES);
print_product_list();
break;

case "recomend":
recommend_product($_POST);
break;
case "del_recom":
delete_recommended_items($HTTP_GET_VARS);
break;
case "add_opt":
add_options($_POST);
break;
case "modify_opt":
modify_options($_POST);
break;
case "del_opt":
del_options($HTTP_GET_VARS);
break;
default :
print_product_list();
break;
}
include("template/footer.php");


function print_add_product_form($category_id = 0) {
global $CFG, $ME;
$frm["categories"] = array($category_id);
$frm["name"] = "";
$frm["description"] = "";
$frm["brief_desc"] = "";
$frm["price"] = "";
$frm["weight"] = "";
$frm["stock"] = "";
$frm["on_special"] = "";
$frm["image_file"] = "";
$frm["product_code"] = "";

$frm["newmode"] = "insert";
$frm["submit_caption"] = "Add Product";

build_category_tree($category_options, $frm["categories"]);
include("template/product_form.php");
}
function print_edit_product_form($id) {
global $CFG, $ME;
$qid = db_query("
SELECT * FROM products
WHERE id = $id
");
$frm = db_fetch_array($qid);

$qid = db_query("
SELECT category_id
FROM products_categories
WHERE product_id = $id
");
$frm["categories"] = array();
while ($cat = db_fetch_object($qid)) {
$frm["categories"][] = $cat->category_id;
}


/* load product options */
$qid_op = db_query("SELECT * FROM product_options where productid ='$id'");
/* set values for the form */

$frm["newmode"] = "update";
$frm["submit_caption"] = "Save Changes";
/* build the categories listbox options, preselect the selected item */
build_category_tree($category_options, $frm["categories"]);
include("template/product_form.php");
}
function delete_product($id) {
global $CFG, $ME;
/* load up the information for the product */
$qid = db_query("
SELECT name
FROM products
WHERE id = $id
");
$prod = db_fetch_object($qid);
/* delete this product */
$qid = db_query("
DELETE FROM products
WHERE id = $id
");

$qid = db_query("
DELETE FROM products_categories
WHERE product_id = $id
");
include("template/product_deleted.php");

}
function insert_product($id, $frm,$form) {
global $CFG, $ME;
$on_special = checked($frm["on_special"]);
$date = date("Y-m-d");

$qid = db_query("
INSERT INTO products (product_code, name,brief_desc, description, price, stock,weight, on_special, status, dateadded)
VALUES ('$frm[product_code]', '$frm[name]', '$frm[brief_desc]','$frm[description]','$frm[price]','$frm[stock]','$frm[weight]', '$on_special', '$frm[status]','$date')
");

$product_id = db_insert_id();

for ($i = 0; $i < count($frm["categories"]); $i++) {
$qid = db_query("
INSERT INTO products_categories (category_id, product_id)
VALUES ('{$frm["categories"][$i]}', '$product_id')
");
}


if(isset($form["userfile"])){
$image = upload_image($form);
db_query("INSERT INTO thumbnails(productid, image, image_type)
VALUES('$product_id','$image','".$form["userfile"]["type"]."')");
}
}
function update_product($id, $frm, $form) {

global $CFG, $ME;
checked($frm["on_special"]);

$qid = db_query("
UPDATE products SET
product_code = '$frm[product_code]'
,name = '$frm[name]'
,brief_desc = '$frm[brief_desc]'
,description = '$frm[description]'
,price = '$frm[price]'
,on_special = '$frm[on_special]'
,weight = '$frm[weight]'
,stock = '$frm[stock]'
,status = '$frm[status]'
WHERE id = $id
");

$qid = db_query("
DELETE FROM products_categories
WHERE product_id = $id
");

if (count($frm["categories"]) == 0) {
$frm["categories"][] = 0;
}
for ($i = 0; $i < count($frm["categories"]); $i++) {
$qid = db_query("
INSERT INTO products_categories (category_id, product_id)
VALUES ('{$frm["categories"][$i]}', '$id')
");
}

if(isset($form["userfile"])){
$image = upload_image($form);

$qid_im = db_query("SELECT * FROM thumbnails WHERE productid='$id'");
$res = db_num_rows($qid_im);
if($res){

db_query("UPDATE thumbnails SET
image = '$image'
,image_type ='".$form["userfile"]["type"]."' WHERE productid = '$id' ");
}else{
db_query("INSERT INTO thumbnails(productid, image, image_type)
VALUES('$id','$image','".$form["userfile"]["type"]."')");
}
}


}
function print_product_list() {
global $CFG, $ME;
require($CFG->libdir.'/pagedresults.php');
$sql = "SELECT p.id, p.name, p.brief_desc , p.price,p.on_special, p.dateadded, c.name AS category
FROM products p, products_categories pc, categories c
WHERE p.id = pc.product_id
AND c.id = pc.category_id ORDER BY p.dateadded desc ";
$rs = new MySQLPagedResultSet($sql,10,$CFG->cnx);
include("template/product_list.php");
}

function recommend_product($frm){
global $CFG, $ME;

if ($frm["selected_productid"] && $frm["productid"]!=$frm["selected_productid"]){
db_query("INSERT INTO product_links(productid1, productid2) VALUES ('$frm[productid]', '$frm[selected_productid]')");
if (isset($frm["bi_directional"])&& $frm["bi_directional"]== "on")
db_query("INSERT INTO product_links(productid1, productid2) VALUES ('$frm[selected_productid]', '$frm[productid]')");
}
print_edit_product_form($frm["productid"]);
}
function delete_recommended_items($frm){

db_query("DELETE FROM product_links WHERE productid1='$frm[productid]' AND productid2='$frm[product_link]'");
print_edit_product_form($frm["productid"]);

}
function add_options($frm){

if ($frm["optclassnew"] && $frm["opttextnew"])
db_query("insert into product_options (productid, optclass, opttext, options) values ('$frm[productid]','$frm[optclassnew]','$frm[opttextnew]','$frm[optionsnew]')");

print_edit_product_form($frm["productid"]);
}
function del_options($frm){
db_query("delete from product_options where optionid='$frm[optionid]'");

print_edit_product_form($frm["productid"]);
}
function modify_options($frm){
while(list($key,$val)=each($frm)) {
if (strstr($key,"-")) {
list($field,$optionid)=split("-",$key);
db_query("update product_options set $field='$val' where optionid='$optionid'");
}
}
print_edit_product_form($frm["productid"]);
}


function upload_image($frm){
global $CFG, $ME, $image_x, $image_y;
$file_temp_dir = "$CFG->imagedir";
if (func_is_image_userfile($frm["userfile"]["tmp_name"], $frm["userfile"]["size"], $frm["userfile"]["type"])) {
move_uploaded_file($frm["userfile"]["tmp_name"], $file_temp_dir."/".$frm["userfile"]["name"]);
$frm["userfile"]["tmp_name"] = $file_temp_dir."/".$frm["userfile"]["name"];
list($image_size, $image_x, $image_y) = func_get_image_size($frm["userfile"]["tmp_name"]);
$fd = fopen($frm["userfile"]["tmp_name"], "rb");
$image = addslashes(fread($fd, $image_size));
fclose($fd);
unlink($frm["userfile"]["tmp_name"]);
return $image;
}
}
?>

right now using this code im uploading images to database as blogs but if anyone can help me out in uploading to a specific directory it would be much better

Regards