How do I disable the Internet connection in Android Emulator?

I am trying to check Internet connectivity on Android using the following method. I have a Wi-Fi connection.

private boolean checkInternetConnection() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    // Test for connection
    if (cm.getActiveNetworkInfo() != null
            && cm.getActiveNetworkInfo().isAvailable()
            && cm.getActiveNetworkInfo().isConnected()) {
        return true;
    }
    else {
        // No conection
        return false;
    }
}

I disconnect my PC from the Internet and then try to run the above method. Still it always returns true!? Why?

From Eclipse

To disable the Internet connection, go to Eclipse and do

menu Window -> Show view -> Other -> Android -> Devices

Now select your running emulator and again go to:

menu Window -> Show View -> Other -> Android -> Emulator Control

Now in that... set Data to Unregister from Home.

From Device and Emulator

On the device or in the emulator, go to:

Setting -> Wireless & networks -> Airplane Mode -> OK