Android - prevent webview reload if screen rotate

I found there are some method to prevent this happen, may be it's all about the API level to work with.
Anyway, I'm working on Android 3.2 + and API level 13. Adding the following declaration in Manifest works prefect.

<activity android:configChanges="orientation|screenSize">

http://developer.android.com/guide/topics/resources/runtime-changes.html