function createTrackingImage(src) {
	var image = document.createElement("img");
	image.src = src;
	image.width = 1;
	image.height = 1;
	image.setAttribute("style", "margin:0px;padding:0px;border-style:none;");
	return image;
}

window.onload = function() {
	var elements = document.getElementsByTagName("span");
	for (var i = 0, n = elements.length; i < n; i++) {
		var elem = elements.item(i);
		if (elem.className) {
			var cName = elem.className;
			var dest = null;
			var trackingImage = null;
			

if (cName == "js-link-1") {
				dest = "http://www.seobook.com/";
				trackingImage =	createTrackingImage("affiliat-etracking-image-link");
			} 

else if (cName == "js-link-2") {
				dest = "http://www.affiliatelink-2.com/";
				trackingImage =	createTrackingImage("http://www.affiliate-tracking-image-2.com/");
			}
			


else if (cName == "js-link-3") {
				dest = "http://www.affiliatelink-3.com/";
				trackingImage =	createTrackingImage("http://www.affiliate-tracking-image-3.com/");
			}




if (dest != null) {
				var a = document.createElement("a");
				a.href = dest;
				a.setAttribute("rel", "nofollow"); 
				a.setAttribute("target", "_blank");
				a.appendChild(elem.cloneNode(true));
				elem.parentNode.replaceChild(a, elem);
				if (trackingImage != null) {
					a.parentNode.appendChild(trackingImage);
				}
			}
		}
	}
};