Nodejs respone.write don't output parameter

I got some annoying error on very simple nodejs response.write from http module. response.write don't output parameter. Help me please !

var server = http.createServer(function(request, response){
    console.log("Connection");
    var pathname = url.parse(request.url).pathname;
    switch(pathname) {
        case '/':
            response.writeHead(200, {"Content-Type": "text/html"});
            response.write("hello world");
            break;
        case '/socket.html':
            fs.readFile(__dirname + pathname, function(error, data) {
                if(error) {
                    response.writeHead(404);
                    response.write("Oops this doesn't exist - socket.html");
                }else {
                    response.writeHead(200, {'Content-Type': 'text/html'});
                    response.write(data, 'utf8');
                }
            });
            break;
        default :
            response.writeHead(404);
            response.write("Oops this doesn't exist - default");
            break;
    }
    response.end();

Above codes block is apart of my server.js file.