var banner = new Array();

banner[0]='https://i1061.photobucket.com/albums/t475/fishe_/Strongworld_Athena_final3.jpg';
banner[1]='https://i1061.photobucket.com/albums/t475/fishe_/Strongworld_Hades_final2.jpg';
banner[2]='https://i1061.photobucket.com/albums/t475/fishe_/Strongworld_Odin_final.jpg';

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