var banner = new Array();

banner[0]='http://img407.imageshack.us/img407/5088/nintendoforever.png';
banner[1]='http://img840.imageshack.us/img840/3888/header1jk.png';
banner[2]='http://img208.imageshack.us/img208/3307/header2gf.png';
document.getElementById('i_logo').src= banner[Math.floor(Math.random()*banner.length)];