function AdRotator(imgTagNameAttribute, adURLs, adImageURLs, rotationTime,
    adRotatorVarName) {
   this.imgTagNameAttribute = imgTagNameAttribute
   this.adURLs = adURLs
   this.adImageURLs = adImageURLs
   this.rotationTime = rotationTime
   this.adRotatorVarName = adRotatorVarName
   this.index = 0
   this.adImages = new Array(adImageURLs.length)
   for(var i=0; i<adImageURLs.length; ++i) {
    this.adImages[i] = new Image()
    this.adImages[i].src = adImageURLs[i]
   }
   this.writeHTML = AdRotator_writeHTML
   this.start = AdRotator_start
   this.rotate = AdRotator_rotate
   this.handleClick = AdRotator_handleClick
  }

  function AdRotator_writeHTML() {
   document.write('<p align="center">')
   document.write('<a href="javascript:void(0)" ')
   document.write('onclick="'+this.adRotatorVarName+'.handleClick()">')
   document.write('<img name="'+this.imgTagNameAttribute+'" border="0" ')
   document.write('src="'+this.adImageURLs[0]+'">')
   document.write('</a></p>')
  }

  function AdRotator_start() {
   window.setInterval(this.adRotatorVarName + '.rotate()', this.rotationTime)
  }

  function AdRotator_rotate() {
   ++this.index
   this.index %= this.adImageURLs.length
   document.images[this.imgTagNameAttribute].src = this.adImages[this.index].src
  }

  function AdRotator_handleClick() {
   setTimeout("window.location.href = '"+this.adURLs[this.index]+"'",500)
  }