output = document.getElementById('output');

        connectBtn.addEventListener('click', () => {
            output.innerHTML = '';
            //socket = new WebSocket('ws://localhost:8888/echo');
            socket = new WebSocket('ws://ws.localhost/echo');

            socket.onopen = () => {
                output.innerHTML += '<p>Connected to WebSocket server</p>';
                connectBtn.disabled = true;
                disconnectBtn.disabled = false;
                sendBtn.disabled = false;
    