At the top of productdetails.asx the following are the two sections that you need to uncomment.  I have uncommented the sections so you should be able to cut and paste the zoom scripts below:
	<%--Zoom Live Server--%>
	<link rel="stylesheet" type="text/css" href="/css/jqzoom.css" />
	<script type='text/javascript' src='/js/jquery-1.3.2.min.js'></script>
	<script src="/js/jqzoom.pack.1.0.1.js" type="text/javascript"></script>
	
	<%--Zoom Uncomment this section if you want to enable zoom--%>
	<script type="text/javascript">
	
	    var jqzoomOptions = {
	        zoomWidth: 300,
	        zoomHeight: 300,
	        title: false
	    }
	    
	    jQuery(function() {
	        jQuery(".jqzoom").unbind();
	        jQuery(".jqzoom").jqzoom(jqzoomOptions);
	    });
	
	    function SwapImage1() {
	
	        var setImage1 = document.getElementById("<%=hdPic1.ClientID%>").value;
	        document.getElementById("<%=Image1.ClientID%>").src = setImage1;
	
	        var setZoomImage1 = document.getElementById("<%=hdZoomPic1.ClientID%>").value;
	        document.getElementById("<%=myMainImage.ClientID%>").href = setZoomImage1;
	
	        //jQuery(".jqzoom").unbind();
	        //jQuery(".jqzoom").jqzoom(jqzoomOptions);
	
	        return false;
	    }