Problema com WebSockets em HTML5!

if ("WebSocket" in window) {
 var ws = new WebSocket("ws://localhost:8080");
 ws.onopen = function() {
 ws.send("message to send");
 };

 ws.onmessage = function (evt) {
 var received_msg = evt.data;
 alert(evt.data);
 };

 ws.onclose = function() {
 alert("WebSocket Closed!");
 };
 } else {
 alert("Websocket is not supported in your browser");
 }

''PEGUEI ESSE CODIGO NA NET E COLEI .HTML''