asp.net中在用ajax格式传递数据到aspx页面时出现乱码

XmlHttp.open("POST", "test.aspx", false); 
XmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
XmlHttp.send("QueryName=" + escape(Queryname) + "&QuerySex=" +escape(Querysex)); 
 
在test.aspx中： 
 代码如下:

string QueryName = HttpUtility.UrlDecode(Request.Params["QueryName"]); 
string QuerySex = HttpUtility.UrlDecode(Request.Params["QuerySex"]);