transparent gif backgrounds

[khayman2001]

Okay, I'm creating a game using php, CSS, and JavaScript, and I would like to change the character's skin color with the onChange attribute of a select field. I have a transparent gif image which is the inverse of the character, and I'm trying to find a way to make the background change behind the transparent gif to change the skin color. Here's the link to the form, but don't submit, as it does nothing yet:

http://www.ravensperch.org/goth/chargen.php

Any help is appreciated, thanks.

[khayman2001]

I forgot to mention that the gif is beneath the Skin Color: field.