title: File upload not working with $_FILES
body: <p>In my PHP web page I have a file type input in a form and when I submit it I can get the file name which was uploaded with <code>$_POST['upload']</code> but if I use <code>$_FILES['upload']['tmp_name']</code> it gives nothing -- why? How can I use <code>$_FILES</code> to get the file to attach it to my email?</p>