totalAds = 7 // total number of ad images

//preload images
if (document.images) {
     bannerAd = new MakeImageArray(totalAds)
   
     bannerAd[1].src = "images/bannerAd1.gif"
     bannerAd[2].src = "images/bannerAd2.gif"
     bannerAd[3].src = "images/bannerAd3.gif"
     bannerAd[4].src = "images/bannerAd4.gif"
     bannerAd[5].src = "images/bannerAd5.gif"
     bannerAd[6].src = "images/bannerAd6.gif"
	  bannerAd[7].src = "images/bannerAd6.gif"
}

function MakeImageArray(n) {
     this.length = n
     for (var i = 1; i<=n; i++) { this[i] = new Image() }
     return this
   }

//start ad rotation
if (document.images) {
adDelay = 4000
adNum = 1  //first ad to display

bannerAd = new Array()
for (i = 1; i <= totalAds ; i++) { 
   bannerAd[i] = new Image(533,125)
   bannerAd[i].src = "images/bannerAd" + i + ".gif"
   }

// set corresponding links for adds.
bannerAdHREF = new Array()
for (i = 1; i < totalAds ; i++) { 
   bannerAdHREF[1] = "subscriptions.html"   
   bannerAdHREF[2] = "webinar2010.html"
	bannerAdHREF[3] = "whychoose.html"
	bannerAdHREF[4] = "webinar.html"
   bannerAdHREF[5] = "whychoose.html#contractors"   
   bannerAdHREF[6] = "webinar2010.html"
   bannerAdHREF[7] = "whychoose.html"
   }
}

function rotateAd() {
   if (document.images) {
      var adURL = document.getElementById("bannerAdURL")
      document.bannerAd.src = bannerAd[adNum].src
      adURL.href = bannerAdHREF[adNum]
      adNum++
      if(adNum > totalAds) {
         adNum = 1
      }
   }
}