Trying to write a form with a file upload page which has a preview option on it. Basically you fill in a form attach a file and ether preview or post. The post works fine but if the preview is choosen it passes all the form variables to a page with lots of hidden inputs to carry the variables onto the final post page. Everything works except the attached file upload which i'm passing on like so...

<input type="hidden" name="files" value="<? $files = urlencode(serialize($_FILES)); echo $files; ?>" />

I can see it on the final page but when i try to move_uploaded_file() it doesn't act like a file - is there an issue with storing the $_FILES variable (under a new name $files), does the file get flushed out of its temporary storage????