These examples demonstrate how it is possbile to use CSS and JavaScript
in order to hide the browse button from a file upload control so that it
looks and works like an ordinary textbox.  Example 1 and 2 are identical,
except that example 2 uses a semi-transparent file upload control to show
how the controls are positioned.

Further description of how this technique works can be found in Peter-Paul Koch's
demonstration page.
http://www.quirksmode.org/dom/inputfile.html