var banner = new Array();

banner[0]='https://i.servimg.com/u/f80/17/79/52/64/ganara12.jpg';
banner[1]='https://i.servimg.com/u/f80/17/79/52/64/ganara13.jpg';
banner[2]='https://i.servimg.com/u/f80/17/79/52/64/ganara14.jpg';
banner[4]='https://i.servimg.com/u/f80/17/79/52/64/ganara15.jpg';';

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