why ain't dis AJAX function woikin'??!

gistfile1.js

<script>
 		var xhr = new XMLHttpRequest();
		var bringItAJAXButton = document.getElementById('load');
		xhr.onreadystatechange = function() {
			if(xhr.readyState === 4) {
				document.getElementById('ajax').innerHTML = xhr.responseText;
			}
		};
		xhr.open('GET', 'sidebar.html');
		function sendAJAX() {
			xhr.send();
			document.getElementById('load').style.display = "none";
		}
		bringItAJAXButton.addEventListener("click," sendAJAX);
  </script>