Thumbnails grid wall as wall paper? [closed]

Question

Closed. This question needs to be more focused. It is not currently accepting answers. Learn more.

---

Want to improve this question? Update the question so it focuses on one problem only by editing this post.

I want to make a wall of thumbnails to suit a screen resolution of 2560x1440px. I want the grid to sit behind my page acting as a background on the site.

However, when the page is scrolled the grid stays still. I have made some CSS and HTML and tested it in Firefox 4 and Chrome which seems to work fine. In IE8 it doesn't work, the page div doesn't overlap the grid wall but sits under it.

When testing CSS / HTML on IE use the proper format. Instead of just throwing the CSS and HTML on the page only.