(function(){

var relative_URI = window.location.href.replace(/^http(s?:\/\/[^\/]*)\/.*$/, 'ws$1/ws');

var ws = new WebSocket(relative_URI);

ws.onmessage = function (evt) {

var received_msg = evt.data;

alert("Message is received..."+received_msg);

};

ws.onopen = function (evt) {

ws.send("test");

};

})();