iframe.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>iframe Window</title>
    <style>
        body {
            background-color: #D53C2F;
            color: white;
        }
    </style>
</head>
<body>

    <h1>Hello there, i'm an iframe</h1>
    <p>Send Message: <button id="message_button">Hi parent</button></p>
    <p>Got Message:</p>
    <div id="results"></div>

    <script>
        // addEventListener support for IE8
        function bindEvent(element, eventName, eventHandler) {
            if (element.addEventListener) {
                element.addEventListener(eventName, eventHandler, false);
            } else if (element.attachEvent) {
                element.attachEvent('on' + eventName, eventHandler);
            }
        }

        // Send a message to the parent
        var sendMessage = function (msg) {
            // Make sure you are sending a string, and to stringify JSON
            window.parent.postMessage(msg, '*');
        };

        var results = document.getElementById('results'),
            messageButton = document.getElementById('message_button');

        // Listen to messages from parent window
        bindEvent(window, 'message', function (e) {
            results.innerHTML = e.data;
        });

        // Send random message data on every button click
        bindEvent(messageButton, 'click', function (e) {
            var random = Math.random();
            sendMessage('' + random);
        });
    </script>
</body>
</html>