// <script src="/socket.io/socket.io.js"></script>
// needs to be included in .html

var socket = io();

document.body.addEventListener('click', function() {
  // Hallo Welt is pushed to backend on body click
  socket.emit('sendMessage', "Hallo Welt");
}, true);

// Message is received from backend
socket.on('getMessage', function(msg){
  console.log(msg);
});