var http = new XMLHttpRequest();
var url = "url";
var params = JSON.stringify({ appoverGUID: approverGUID });
http.open("POST", url, true);
http.setRequestHeader("Content-type", "application/json; charset=utf-8");
http.setRequestHeader("Content-length", params.length);
http.setRequestHeader("Connection", "close");
http.onreadystatechange = function() {
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
http.send(params);