onmessage = function(evt) { if (evt.data != 0) { var worker = new Worker("broadcastchannel_worker.js"); worker.onmessage = function(evt) { postMessage(evt.data); } worker.postMessage(evt.data - 1); return; } var bc = new BroadcastChannel('foobar'); bc.addEventListener('message', function(event) { bc.postMessage(event.data == "hello world from the window" ? "hello world from the worker" : "KO"); bc.close(); }); postMessage("READY"); }