Hello Friendly Neighborhood JavaScript Expert!

I've got myself into some trouble, I really hope you can help me out! I promised a client some javascript functionality without actually knowing how to do it. It just seemed plausible so I gave my guarantee. The whole thing started when we decided it would be neat if the web page looked slightly different every time you visited.

The functionality I'm looking for will fade the CSS associated to the html body tag. The tiled background image in particular.

I have over 50 seamless tile background images of various dimensions stored in my default image folder. I'm hoping to find some script that will select and display one of the images at random and then fade to a new one every 10 or 20 seconds.

I have no idea how to start writing this code. I sure hope it's possible.

It might work if I had some script that replaced the background attribute of the body tag with an animation.. selecting from an array of image paths?

Can you help me figure this out? Is it even possible?