Cross-Domain Browser Communication with HTML5 Window#postMessage; only loading windows if they don't already exist

01.getting.windows.js

// getting the window of an iframe
receiver = document.getElementById('frameId').contentWindow;

// opening a named window to another application
receiver = window.open('http://anotherdomain.dev/path', 'myPopup');

// getting a named window WITHOUT loading any content
receiver = window.open(null, 'myPopup');

02.postMessage.js

receiver.postMessage('TET-SU-OOOOOOOO!!!', 'http://anotherdomain.dev');

03.listening.js

window.addEventListener('message', function(event) {
  // handle event ...
}, false);

04.check.origin.js

if (event.origin === 'http://trusteddomain.dev') {
  // continue handling
}

05.accessing.data.js

console.log(event.data); // with previous postMessage() example, this prints 'TET-SU-OOOOOOOO!!!'

06.posting.back.js

event.source.postMessage('KA-NA-DAAAAAAAAAA!!!', event.origin);

07.parent.js

(function initializeOpenUniquePopUp() {
  var openedDomain = 'http://opened.dev';
  var trackedWindows = {};

  window.openUniquePopUp = function(path, windowName, specs) {
    trackedWindows[windowName] = false;
    var popUp = window.open(null, windowName, specs);
    popUp.postMessage('ping', openedDomain);
    setTimeout(checkIfOpen, 1000);

    function checkIfOpen() {
      if(!trackedWindows[windowName])
        window.open(openedDomain + path, windowName, specs);
    }
  };

  if(window.addEventListener)
    window.addEventListener('message', onPingBackMessage, false);
  else if (window.attachEvent)
    window.attachEvent('message', onPingBackMessage, false);
  
  function onPingBackMessage(event) {
    if(event.origin == openedDomain) {
      trackedWindows[event.data] = true;
    }
  }
})();

window.openUniquePopUp('/a-path', 'uniqueId', 'width=320,height=480');

08.child.js

(function listenForPings() {
  var openerDomain = 'http://opener.dev';

  if(window.addEventListener)
    window.addEventListener('message', onPingMessage, false);
  else if (window.attachEvent)
    window.attachEvent('message', onPingMessage, false);
  
  function onPingMessage(event) {
    if(event.origin == openerDomain)
      event.source.postMessage(window.name, event.origin);
  }
})();

09.jQuery.window.event.listening.js

jQuery(window).on('message', onPingBackMessage);  
function onPingBackMessage(event) {
  if(event.origin == openedDomain) {
    var messageEvent = event.originalEvent;
    trackedWindows[messageEvent.data] = true;
  }
}

would be great if you can share the example for this cross domain messaging?