img=new Array(5)
img[0]="<img src='http://www.therocos.com/images/header/01.jpg'>";
img[1]="<img src='http://www.therocos.com/images/header/02.jpg'>";
img[2]="<img src='http://www.therocos.com/images/header/03.jpg'>";
img[3]="<img src='http://www.therocos.com/images/header/04.jpg'>";
img[4]="<img src='http://www.therocos.com/images/header/05.jpg'>";
imgNo=Math.floor(5*Math.random());ss
document.write(img[imgNo]);