<html>
    <head>
        <script>
            function openPopUpWindow() {
                var popUpWindow = window.open('https://www.webkit.org', '', 'width=300, height=300');
                if (popUpWindow) {
                    try {
                        window.webkit.messageHandlers.testHandler.postMessage("pop-up-allowed");
                    } catch(e) { }
                } else {
                    try {
                        window.webkit.messageHandlers.testHandler.postMessage("pop-up-blocked");
                    } catch(e) { }
                }
            }
        </script>
    </head>
    <body onload="openPopUpWindow()">
    </body>
</html>