bg = new Array(0); 
bg[0] = 'ttest.files/top1.gif'
bg[1] = 'ttest.files/top3.jpg'
bg[2] = 'ttest.files/top2.gif'
bg[3] = 'ttest.files/top4.jpg'
bg[4] = 'ttest.files/top5.jpg'
index = Math.floor(Math.random() * bg.length);
document.write("<td height='100' colspan='2' background="+bg[index]+">");