var worker = new Worker("worker.js");
worker.onmessage = function (event) {
  var message = event.data;
  if (message.type == "ready") {
    outputElement.textContent = "Loaded";
    worker.postMessage({
      type: 'command',
      arguments: ['-help']
    })
  } else if (message.type == "stdout") {
    outputElement.textContent += message.data + "\n";
  } else if (message.type == "start") {
    outputElement.textContent = "Worker has received command\n";
  }
};