function random_imglink(){
  var myimages=new Array()

  myimages[1]="images/band1.png"
  myimages[2]="images/band2.png"
  myimages[3]="images/band3.png"
  myimages[4]="images/band4.png"


  var ry=Math.floor(Math.random()*myimages.length)

  if (ry==0)
     ry=1
     document.write('<img src="'+myimages[ry]+'" alt="rhesus" width="508" height="400" />')
}

  random_imglink()