/*
    This library supports DHTML rotating banners. 
    Usage Example:
      
    <script language="javascript">
        var tag_key = new Banner('tag_key','tag_key_link', 3000);
        tag_key.images[0] =  new Object();
        tag_key.images[0].src =  "banners/1.gif";
        tag_key.images[0].link = "http://www.eblox.com";
        tag_key.images[0].target = "tag_key";
        tag_key.images[0].tracker = "/banners/home/new_products";
        tag_key.images[1] =  new Object();
        tag_key.images[1].src =  "banners/2.gif";
        tag_key.images[2] =  new Object();
        tag_key.images[2].src =  "banners/3.gif";
        tag_key.images[2].link = "http://www.cnn.com";
        banners[banners.length] = tag_key;
    </script>
    <a id="tag_key_link"><img id="tag_key" border="0"/></a>
    
*/


    var banners = new Array();
    
    function startBanners () {
        for(var i=0; i<banners.length; i++) {
        	banners[i].startRotation();
        }
    }
    
    window.addOnloadListener(startBanners);
    
    
    function Banner(imageId, linkId, interval) {
        this.index = 0;
        this.images = new Array();
        this.imageId = imageId;
        this.linkId = linkId;
        this.interval = interval;
        this.name=imageId;
    }
    
    Banner.prototype.callTracker = function() {
        urchinTracker("/banners/" + this.tracker);
    }
    
    Banner.prototype.rotate = function () {
		var banner = document.getElementById(this.imageId);
		var link = document.getElementById(this.linkId);
		banner.src = this.images[this.index].src;
		if(this.images[this.index].link) {
			link.href = this.images[this.index].link;
		} else {
			link.removeAttribute("href");
		}
		if(this.images[this.index].target) {
			link.target = this.images[this.index].target;
		} else {
			link.removeAttribute("target");
		}
		if(this.images[this.index].tracker) {
		    link.tracker = this.images[this.index].tracker;
		    link.onclick = this.callTracker;
		} else {
		    link.removeAttribute("tracker");
		    link.onclick = null;
		}
		this.index = ++this.index % this.images.length;	
	}
        
    Banner.prototype.startRotation = function () {
        this.rotate();
        window.setInterval(this.name+'.rotate()',this.interval);
    }