window.addEventListener('beforeunload',function (e){
    return ((e||window.event).returnValue) = 'You are about to leave the chat.';
});

// ==UserScript==
// @name        Confirm Navigation on gdnet Chat
// @namespace   fastcall22.com
// @include     http://www.gamedev.net/chat/*
// @version     1.0
// @grant       none
// ==/UserScript==

(function(){
	window.addEventListener('beforeunload',function (e){
		return ((e||window.event).returnValue) = 'You are about to leave the chat.'
	})
})();