Implement HTTP post in Javascript

Hello I am doing an analytical project for delay tolerance for various applications. So I need to 开发者_如何转开发build a portable application to take user feedback. I am trying to do this using Javascript. Whenever, the user clicks a button on the JS page I have to send a request to the HTTP server setup on the router to change the delay. I want to implement this as a HTTP request (POST). I know Javascript. I found ways like Jquery, Protocol but I intend to send only one parameter(need not be hidden) Can some one help me with this?

Your asking how to send a ajax post w/ a url param?

xhr=new XMLHttpRequest();
xhr.open("POST", "http://helloasdf.cloudfoundry.com/post.token?key=asdf", true);
xhr.send(null);