var banner = new Array();

    banner[0]='http://img404.imageshack.us/img404/5296/banner1pj.jpg';
    banner[1]='http://img688.imageshack.us/img688/9282/banner2dx.jpg';
    banner[2]='http://i43.servimg.com/u/f43/12/63/86/16/banner20.jpg';
    banner[3]='http://i43.servimg.com/u/f43/12/63/86/16/banner19.jpg';
    banner[4]='http://i43.servimg.com/u/f43/12/63/86/16/banner18.jpg';
    banner[5]='http://i43.servimg.com/u/f43/12/63/86/16/banner17.jpg';
    banner[6]='http://i43.servimg.com/u/f43/12/63/86/16/banner16.jpg';

    document.getElementById('i_logo').src= banner[Math.floor(Math.random()*banner.length)];