Can't get image file in form to attach to submission

Hi I hope somebody can help

I have simple form for user to submit their details to me, it was working fine, until I tried to allow them to select an image file in the form and then get this file to attach to the rest of the submission.

I have tried with both of the following:-
enctype="text/plain" &
enctype="multipart/form-data" when I use the later the form does not automatically submit it only opens outlook express and when I use the "text/plain" I just get the actual text which is shown on the form (not the file attched)

Please help !!