function createXMLHttpRequest() {
		var xmlHttp;
		try
		   {
		 
		     // try to create XMLHttpRequest object
		     xmlHttp = new XMLHttpRequest();
		
		   }
		   catch(e)
		   {
		   var prefixes = ["MSXML2.XmlHttp","Microsoft.XmlHttp","MSXML3.XmlHttp", "MSXML.XmlHttp"];
		     // assume IE6 or older
		   	for (var i = 0; i < prefixes.length; i++) {
				try{xmlHttp = new ActiveXObject(prefixes[i]);}catch(ex){};
			}
		       
		   }
		   // return the created object or display an error message
		   if (!xmlHttp)
		     alert("Error creating the XMLHttpRequest object.");
		   else
		     return xmlHttp;
  }

function add2Cart(productId) { //在远方www.jscode.cn
pageTracker._trackEvent('放入购物车', '<%= product_name%>', '/myorder/cart.jsf?productId='+productId);
	var xmlHttp=createXMLHttpRequest();
 	var url="/myorder/cart.jsf?productId="+productId;
 	xmlHttp.open("post",url, true);
	xmlHttp.onreadystatechange = function () {	
		if(xmlHttp.readyState==4){
			 if (xmlHttp.status == 200){

                   
                   //背景
  var bgObj=document.getElementById("bgDiv");
  bgObj.style.width = document.body.offsetWidth + "px";
  bgObj.style.height = screen.height + "px";

//定义窗口
  var msgObj=document.getElementById("msgDiv");
  msgObj.style.marginTop = -75 +  document.documentElement.scrollTop + "px";

//关闭
  document.getElementById("msgShut").onclick = function(){
  bgObj.style.display = msgObj.style.display = "none";
  }
  var msgDetail=document.getElementById("msgDetail");
  msgObj.style.display = bgObj.style.display = "block";
  msgDetail.innerHTML="商品已成功加入到购物车<br><br><A href='#' onclick='document.getElementById(\"bgDiv\").style.display = document.getElementById(\"msgDiv\").style.display = \"none\"'><img src=/version2/images/msg_button1.gif /></A> <A href=/myorder/cart.jsf><img src=/version2/images/msg_button2.gif /></A>"          
             }
		} 
	}
	xmlHttp.send(null);				
}