var banner = new Array();

banner[0]='https://i.imgur.com/RvUaW0W.png';
banner[1]='https://i.imgur.com/0QI1kCo.png';
banner[2]='https://i.imgur.com/GBVApRc.png';
banner[3]='https://i.imgur.com/liFnPTA.png';
banner[4]='https://i.imgur.com/Z6HpWQH.png';
banner[5]='https://i.imgur.com/8CzA2KQ.png';


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