ws_test.js

function WebSocketTest()
{
    if ("WebSocket" in window)
    {
        var ws = new WebSocket("ws://localhost:9990/ws?param=valu&another_param=another_value");
        ws.onmessage = function(evt)
        {
            var msg = evt.data;

            var div = document.createElement('div');
            div.textContent = msg;
            document.body.appendChild(div);
        };
    }
    else
    {
        alert("This browser does not support WebSockets.");
    }
}