<html>
    <script language="javascript">
        /* This function is invoked by the activity */
        function wave() {
            alert("1");
            document.getElementById("droid").src="android_waving.png";
            alert("2");
        }
    </script>
    <body>
        <!-- Calls into the javascript interface for the activity -->
        <a onClick="window.demo.clickOnAndroid()"><div style="width:80px;
            margin:0px auto;
            padding:10px;
            text-align:center;
            border:2px solid #202020;" >
                <img id="droid" src="android_normal.png"/><br>
                Click me!
        </div></a>
    </body>
</html>
My question is: What is "window.demo.clickOnAndroid()"?
I know that clickOnAndroid is a method in my Android application. But what is window and demo? My file is called demo.html. Is that it?