var banner = new Array();

banner.push('https://i.servimg.com/u/f19/12/99/72/36/hip_ho10.jpg');
banner.push('https://i.servimg.com/u/f19/12/99/72/36/th/miami_10.jpg');
banner.push('https://i.servimg.com/u/f89/12/99/72/36/header10.jpg');

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