HTML redirect help

[BC]

What I am doing is making a redirect page based on your resolution. My problem is this. I have a friend that gave me the code to put a button on the page (an enter button) what I want to do is put a picture on it instead. here is the code that I have for the button how do I make it in to the picture

(form>
(input type=button value="Enter!" onClick="redirectPage()">
(/form>