adrotation = new Array ("graphics/ad-conguide.gif")

adURL = new Array ("http://www.nicholas.duke.edu/institute/ccpp/convenientguide/")



imgCtAd = adrotation.length




function chooseAd() {
  if (document.images) {
  randomNumAd = Math.floor ((Math.random()* imgCtAd))
  document.ad.src = adrotation[randomNumAd]
}
}


function newLocationAd() {
   document.location.href = adURL[randomNumAd]
}