$_FILES array returns undefined index

[<Ron.Herhuth@xxxxxxxxxxxxxxxxx>]

I'm trying to do a file upload using PHP.  I am using this form element on
th first page:
<input type="FILE" name="userfile" size="36">

On the second page I'm attempting to access the file name to figure out
how to access it using this code:
echo $_FILES['userfile']['name'];

I get an undefined index userfile...error

What am I doing/not doing right here?

Thanks,
ROn