Android :: Loading Cache When Offline In Android Webview

i have an application which loads urls from a website. Now i want that the aplication uses the cache when offline. But i just get the failure site which says that im not connected to the website. At first i set the Cachmode to Load_Normal but this doesnt help. Next i tried a realy "silly" approach using the ConnectivityManager:

cm = (ConnectivityManager) this.getSystemService(Activity.CONNECTIVITY_SERVICE);

if(cm.getActiveNetworkInfo().isConnected()){
mfnWebView.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);
mfnWebView.loadUrl(url);
}
else{
mfnWebView.getSettings().setCacheMod e(WebSettings.LOAD_CACHE_ELSE_NETWORK);
mfnWebView.loadUrl(url);
}

but this just leads to crashing the application. Is there a simple way to load the cache when offline and existing. And just if not existing showing the failure message.