OK with variable but not OK with fumctions. source properties. window.postMessage() provides a controlled mechanism to securely circumvent this restriction (if used properly). Its also not part of the W3C HTML5 specification at the time of this writing. You can browse them on the Mozilla Feature Policy Documentation. A first attempt way be to go right at the information as if it was contained within our own page. Besides, its not that hard to secure them, so you wont have to worry about your users computer becoming infected. Hopefully, this new feature will provide a clear and safe method of interacting with iFrames. Multiple data items can be sent as an array. So if you're sending a message to an