var images = new Array('banner-aroma.jpg','banner-drumsara.jpg','banner-hubble.jpg')
var image = document.getElementById('topimage')
if (image) {
  var path = image.src
  var pathslash = path.lastIndexOf('/')
  if (pathslash == -1) {
      path = ''
  } else {
    path = path.slice(0,pathslash+1)
  }
  var index = Math.floor(Math.random() * images.length)
  image.src = path+images[index]
}