Cross-Origin Communication (postMessage)
Instructions: Test communication between this parent window and the iframe below.
- Click the "Send Message to Iframe" button.
- This sends a message to the iframe, which should then display it.
- The iframe will automatically send a reply back to this parent window.
Validation: Your script should verify that the reply message "Message received by iframe!" appears in the output box on this page.
Message from Iframe:
No message received yet.