Cross domain iframe issue

Question

For say i have a Site called example.com on which iframe is embedded of domain iframe.net, now i want to read the content of iframe and pass some parameter to display a text

Answer 1

In Internet Explorer 8, events passed as a parameter may be null, that is why you need to access the event in a different manner:

In frame.html:

window.onmessage = function(event) {
   var evt = event || window.event;
   evt.source.postMessage('Message from iFrame', evt.origin);
};

On main.html:

window.onmessage = function(event) {
   var evt = event || window.event;
   alert(evt.data);
};

The event is triggered the same way as Rob W has presented:

document.getElementById('frameId').contentWindow.postMessage('message','*');