<!-- Paste this code into an external JavaScript file named: bannerRotator.js  -->

/* This script and many more are available free online at
The JavaScript Source :: http://javascript.internet.com
Created by: Scragar ::
Licensed under: Public Domain */

 function BannerRotator(){
// first, defaults:
 this.timer = 2;
 this.bannerNum = 0;// -1 = random
// then normal init work
 this.banners = [];
 this.binding = null;
 this.timeout = null;

 this.add = function(){// add a banner to the array
   this.banners[this.banners.length] = [arguments[0], arguments[1]];
 }

 this.bind = function(){// bind to an element
   if(typeof arguments[0] == 'string')
     this.binding = document.getElementById(arguments[0]);
   else
     this.binding = arguments[0];
   this.rotate();
 }

 this.rotate = function(){// the actual image rotator
   if( ! this.empty())
     return;
   var showNum, tmpA = document.createElement('a'), tmpImg = document.createElement('img');

   if(this.bannerNum < 0)// random
     showNum = Math.floor(Math.random()*this.banners.length);
   else// syncronous
     showNum = this.bannerNum=(++this.bannerNum >= this.banners.length)?0:this.bannerNum;

   tmpA.href = this.banners[showNum][0];
   tmpImg.src = this.banners[showNum][1];
   tmpA.appendChild(tmpImg);
   this.binding.appendChild(tmpA);
 }

 this.empty = function(){// empty the element if possible
   if(this.binding == null)
     return false;
   while(this.binding.hasChildNodes())
     this.binding.removeChild(this.binding.firstChild);
   return true;
 }

 this.startTimer = function(){// start the loop, normaly done during page load.
   this.stopTimer();
   this.timeout = window.setInterval(
     (function(x){
       return function(){
         x.rotate();
       }
     })(this), this.timer*1000);
 }

 this.stopTimer = function(){// stop the loop, nice to make available via a button.
   if(this.timeout != null)
     window.clearInterval(this.timeout);
   this.timeout = null;
 }
}// JavaScript Document