Is there a way I can hide the text box of a form <input type = file...

I don't know off the top of my head but how about a border=0 in there somewhere?

If that doesn't work you can make everything the same color and it would not show up.

use the visible [true or false] control attribute on a callback. See this http://www.daniweb.com/forums/thread86493.html for an example.

Q..

Taking the previous recommendation a step further, you could also use jQuery to show and hide it on demand pretty simply.

http://docs.jquery.com/Hide