Internet explorer IE中带xDomain请求的跨域jquery ajax请求不起作用

我使用以下代码在IE中使用xDomain请求生成跨域jquery ajax请求

var xdr;  
 var URL=parentDomain+"/chat/getmessagesservlet";

 if (jQuery.browser.msie && window.XDomainRequest) {  

   // Use Microsoft XDR
   var xdr = new XDomainRequest();
    xdr.open("POST", URL + '?to='+chatboxtitle+'&yourName='+myName+'&chatBoxIndex='+tabIncr);
    xdr.onload = function () {
   var dom  = new ActiveXObject("Microsoft.XMLDOM");
   dom.async = false;
  JSON = $.parseJSON(xdr.responseText); 
   if (JSON == null || typeof (JSON) == 'undefined') {
    JSON = $.parseJSON(data.firstChild.textContent);   
   }

    processData(JSON); // internal function
   }; 

   xdr.onerror = function() {
     _result = false;    
    };
   xdr.send();

    } else {
    $.ajax({ 
      type: 'POST', 
       url: URL,   
          processData: true,
          data: {'to':chatboxtitle,'yourName':myName,'chatBoxIndex':tabIncr}, 
           dataType: "json",
          async: false,
          success: function (data) {
            processData(data);   
           }
});

}'

response.setHeader("Access-Control-Allow-Origin","*");   
response.setHeader("Content-Type","text/plain");
response.setHeader("Access-Control-Allow-Methods"," GET, POST");
response.setHeader("Access-Control-Allow-Headers", "Content-Type"); 

另外，我在服务器端设置了头，如下所示：

response.setHeader("Access-Control-Allow-Origin","*");   
response.setHeader("Content-Type","text/plain");
response.setHeader("Access-Control-Allow-Methods"," GET, POST");
response.setHeader("Access-Control-Allow-Headers", "Content-Type"); 

但在IE8和IE9中，它不起作用。ResponseText返回null或为空。 我已经看到了使用jQuery

response.setHeader("Access-Control-Allow-Origin","*");   
response.setHeader("Content-Type","text/plain");
response.setHeader("Access-Control-Allow-Methods"," GET, POST");
response.setHeader("Access-Control-Allow-Headers", "Content-Type"); 

.ajaxTransport( dataType, handler(options, originalOptions, jqXHR)

或

response.setHeader("Access-Control-Allow-Origin","*");   
response.setHeader("Content-Type","text/plain");
response.setHeader("Access-Control-Allow-Methods"," GET, POST");
response.setHeader("Access-Control-Allow-Headers", "Content-Type"); 

可以进行跨域请求，但我不知道如何在代码中使用它。 在选项和原始选项参数中要传递的值是什么？ 请为我提供解决此问题的指导。

这可能有助于：

response.setHeader("Access-Control-Allow-Origin","*");   
response.setHeader("Content-Type","text/plain");
response.setHeader("Access-Control-Allow-Methods"," GET, POST");
response.setHeader("Access-Control-Allow-Headers", "Content-Type"); 

xdr.onprogress = function () { }; //Needed to save IE9 from melting.