var banner = new Array();

banner[0]='http://i54.tinypic.com/wl3ko0.png';
banner[1]='http://i54.tinypic.com/2u6yyoy.jpg';
banner[2]='http://i54.tinypic.com/2a50ksh.png';
banner[3]='http://i52.tinypic.com/2uhbw9x.png';

document.getElementById('logo').firstChild.src= banner[Math.floor(Math.random()*banner.length)];
setInterval("document.getElementById('logo').firstChild.src= banner[Math.floor(Math.random()*banner.length)];",99000);