url=new Array()
     url[0]="test/1/test1.html"
     url[1]="test/2/test1.html"
     url[2]="test/3/test1.html"
     url[3]="test/4/test1.html"
function rand()
   {
     now=new Date()
     num=(now.getSeconds())%4
     window.open(url[num], 'test', 'height=400,width=300,top=130,left=150')
   }