Looking for browser compatibility, noticing some hovers don't work in certain browsers, what might be the best way too display the image hover?

- combine the 2 images into one and adjust the 'background-position' for hover?
(this be proportational on widely varying screen sizes?)

- use an 'img id' along with a 'div id' ?

And I beleive there is also a way to set an anchor.

What say us?