I am not sure of the rules as far as putting up a file goes, but I am trying to get an image to change depending on what button is pressed, I wouldn't figure this would be too hard for most of you here but I am getting a bit lost, any help would be appreciated and I can provide the .psd, however it says that the 900kb file size exceeds the limit so I dunno what to do there.

I thank you in advance, it would get me out of a bind if I could solve this issue.