Imagevote script problems

Hi all!
Does anyone know the imagvote script? like the one from the site
hotornot.com... I've tried to put this system of voting on my own site,
hosted localy. Everything's fine except with the image uploading. Could
someone help me to fix this problem and find the correct settings in order
to make this work please?
here's the part of the script that I think it's the problem...
// file uploading options
$allowupload = "1"; // Allow users to upload pictures? 1 = Yes / 0 = No
$uploadurl = "http://localhost/contrib/"; // URL to Upload Directory (with
trailing slash)
$uploadpath = '/submitimg/'; // Server Path to Upload Directory (with
trailing slash)
$uploadsize = "200"; // Maximum file size for image uploads, in kilobytes
(100 = 100k)
$chmod = "yes"; // Uncomment this line if your server has an issue setting
permissions on uploads

If someone wants to test it on-line here's the link: www.jemepresente.com
and then click on inscription... Sorry but it's in french (and sorry for my
bad english too! ;-)