Page not working in IE 7 & 8, but is fine in IE9

Hello all,

I have a slider puzzle that I’m working on. It works fine in Safari/Firefox on the Mac and PC. It works fine in IE9, and it even works fine on the iPad and iPhone. Where it doesn’t work is in IE 7 & 8.

I don’t know enough to understand why it doesn’t work in IE 7/8, but would like to know if someone can help me to figure out why and to fix it.

The link is

Thanks so much.

wc3, visit there site and check your site if its folowing there standards, if you do that you will in 99% of the cases see a good site, same in all browsers in other words: crowbrowser save.

Thanks. I’ll give it a try but I’m not really sure what I’m looking for as I’m pretty raw at html 5/cross browser stuff. The puzzle was chosen off the web and I’m trying to get it to work as best as I can.