Error Logging With AJAX

<html>
	<head> 
		<title>Logger Test</title>
		<script type="text/javascript" src="prototype.js"></script>
		<script type="text/javascript" src="ErrorLogger.js"></script>
		<script type="text/javascript">
			Event.observe(window, 'load', function(){
				var er = new ErrorLogger('TestResult.html',   {
					onSuccess : function()    {
						$('btn').setStyle({'backgroundColor' : 'red'});
					},    
					onError : function()    {
						alert('An error occurred on the page. Run for your life!');
					}   
				});  
			}); 
		</script>
	</head>
	<body>

		<button id="btn" onclick="nonExistentFunction()">Throw Error</button>
	
	</body>
</html>