Unless I'm just overlooking it, you don't have a copy function in your script.
You might try using something like this:
$FileName = $_FILES["$Image"]["name"];
$TempName = $_FILES["$Image"]["tmp_name"];
(copy ($TempName, "".$DirectoryPathName."/".$FileName.""))
// A couple of more image functions are:
$FileType = $_FILES["$Image"]["type"];
$FileSize = $_FILES["$Image"]["size"];
see:
PHP Manual
That way the temp name (which might be something like 'xeyst4e7se') is copied to the uploaded file name and then placed on the server.
Also, in the other part(s) of your script $HTTP_POST_VARS has been replaced with a newer variable, $_POST.