noob question.. about header images..

[chiaki06]

hey..
how do i change the header image of my site everytime it loads?
i want to have a random header image effect for every visit or refresh on the site.. can anyone give me a javascript code that does this function? thanks!
sorry if theres another thread like this, kindly link me pls. thanks XD

[spasticus]

look at http://www.computerhope.com/j18.htm