uses each of the XMLHttpRequest. It POSTs a string of text to a server and ignores any response the server sends.

postMessage.js

function postMessage(msg) {
 var request = new XMLHttpRequest(); // New request
 request.open("POST", "/log.php"); // POST to a server-side script
 // Send the message, in plain-text, as the request body
 request.setRequestHeader("Content-Type", // Request body will be plain text
 "text/plain;charset=UTF-8");
 request.send(msg); // Send msg as the request body
 // The request is done. We ignore any response or any error. 
}