Check Network Connection

I want to check that the network connection is alive on the phone from program but when i try to run this code

Code:
private boolean isOnline() {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
return true;
}
return false;
}

I get the message "Sorry 'Appname' is stopped unexpectedly. Try again".I might have to search the solution elsewhere, i added permissions for network, run the application and got the same error but when i tried to start it from the menu it said application not installed.