does jsonp use the xmlhttprequest object code example
Example: how to add json data to xmlhttprequest
var xmlhttp = new XMLHttpRequest(); // new HttpRequest instance
var theUrl = "/json-handler";
xmlhttp.open("POST", theUrl);
xmlhttp.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xmlhttp.send(JSON.stringify({ "email": "[email protected]", "response": { "name": "Tester" } }));