Access WCF service using xmlhttprequest

var xhr;

if (window.XMLHttpRequest) {
    xhr = new XMLHttpRequest();
}
else if (window.ActiveXObject) {
    xhr = new ActiveXObject('Microsoft.XMLHTTP');
}
else {
    throw new Error("Could not create XMLHttpRequest object.");
}

xhr.open("POST", "http://localhost/wcfService/service.svc/GetStatus", true);

xhr.onreadystatechange = function() {
    if (xhr.readyState === 4) {
        alert(xhr.responseText);

    }
};
xhr.setRequestHeader("content-type", "text/xml; charset=utf-8");

var postData = '{id:"E757A1EA-AE50-4A0A-8DE1-26345DDDBD0A" }';
xhr.send(postData);