I'm trying to log (and later modify) the data XMLHttpRequest sends to a server by overriding XMLHttpRequest.send function.

My function logs the data correctly to the console, however the request doesn't finish, therefore the browser keeps waiting for the response indefinitely.

Any ideas what's wrong with the code?

XMLHttpRequest.prototype.realSend = XMLHttpRequest.prototype.send;

var newSend = function(vData) { console.log(data:  + vData); realSend(vData); };

XMLHttpRequest.prototype.send = newSend;