var banner = new Array();

banner[0]='http://img517.imageshack.us/img517/8664/trompeuses.png';
banner[1]='http://img225.imageshack.us/img225/5174/headersmurmures2.png';
banner[2]='http://img230.imageshack.us/img230/8748/header3fin2.png';
banner[3]='http://img121.imageshack.us/img121/5222/headers7.png';
banner[4]='http://img20.imageshack.us/img20/8987/elamentiicopie.jpg';

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