var banner = new Array();

banner[0]='https://i.servimg.com/u/f23/14/63/51/15/logore10.jpg';
banner[1]='https://i.servimg.com/u/f23/14/63/51/15/logore11.jpg';
banner[2]='http://img692.imageshack.us/img692/9048/niponsekaipsd2.jpg';
banner[3]='http://img84.imageshack.us/img84/5182/niponsekaipsd.jpg';
banner[4]='http://img63.imageshack.us/img63/6328/48446989.jpg';
banner[5]='http://img594.imageshack.us/img594/4048/37036752.jpg';
banner[6]='http://img100.imageshack.us/img100/5387/76197710.jpg';
banner[7]='http://img706.imageshack.us/img706/1183/98729179.jpg';
banner[8]='http://img692.imageshack.us/img692/9048/niponsekaipsd2.jpg';
banner[9]='http://img218.imageshack.us/img218/905/logore2210.jpg';
banner[10]='http://img266.imageshack.us/img266/6770/logore102.jpg';
banner[11]='http://img823.imageshack.us/img823/6250/logore10.jpg';
banner[12]='http://img179.imageshack.us/img179/4507/logosre10.jpg';
banner[13]="http://img696.imageshack.us/img696/4355/logore11copia.jpg";

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