PHP Upload File

Dobrý den potrebocal bych pomoc s php soubourem
potreboval bych kdyz napisu do url

http://MOJESTRANKA.cz//upluploads/imageuploader.ph p?action=add&userfile=C:\Users\Saint\Desktop\obrazek.jpg
aby to nahralo obrazek na web
dekuju za pomoc

<?php
$action = $_GET['action'];
$userfile = $_GET['userfile'];

if($action == "add"){
$realname = $HTTP_POST_FILES['userfile']['name'];
if (is_uploaded_file($HTTP_POST_FILES['userfile']['tm p_name']))
{
copy($HTTP_POST_FILES['userfile']['tmp_name'], "./uploads/$realname");
echo "Upload Filename: " . $HTTP_POST_FILES['userfile']['name'];
}
else{
echo "Upload not complete";
}
}
?>