Off Topic: Rotating header image and why I didn't post yesterday.

So, yeaterday I didn't post becuase I was trying to get the header image with my title on to change each vist or just every now and again. I used this site but I couldn't get it to work. If anybody has a link please tell me. I got the idea of an image with my title on it from pathfinder but i want it to change regularly. Please help.

Thanks for reading,

Jacob.