var DataToSend = "id=1&word=hello";
var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
xmlhttp.Open("POST","Receiver.asp",false);
//关键在下面这句
xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlhttp.send(DataToSend);
alert(xmlhttp.responseXML.xml);