var banner = new Array();

banner[0]='http://img256.imageshack.us/img256/7295/logo1simmystery.png';
banner[1]='http://img256.imageshack.us/img256/7295/logo1simmystery.png';
banner[2]='http://img256.imageshack.us/img256/7295/logo1simmystery.png';
banner[3]='http://img256.imageshack.us/img256/7295/logo1simmystery.png';
banner[4]='http://img256.imageshack.us/img256/7295/logo1simmystery.png';
banner[5]='http://img807.imageshack.us/img807/9979/logo2simmystery.png';
banner[6]='http://img807.imageshack.us/img807/9979/logo2simmystery.png';
banner[7]='http://img807.imageshack.us/img807/9979/logo2simmystery.png';
banner[8]='http://img807.imageshack.us/img807/9979/logo2simmystery.png';
banner[9]='http://img807.imageshack.us/img807/9979/logo2simmystery.png';

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