var banner = new Array();

banner.push('https://i.servimg.com/u/f66/13/96/81/40/axlees11.jpg');
banner.push('https://i.servimg.com/u/f66/13/96/81/40/bv020112.jpg');
banner.push('https://i.servimg.com/u/f66/11/66/98/84/exempl10.jpg');
banner.push('https://i.servimg.com/u/f46/13/96/81/40/eggman10.png');

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