I've seen this on a few sites but I'm not really sure how to incorporate it into my own site. Specifically, say I have a website and I have 3 or 4 different headers that I'd like to rotate as the main header each time the page is refreshed. Is there particular php coding I should add to my header.php file located at my site root or is the coding theme specific?

Also, what coding would be used to make this possible?

Thanks,

Ken