Apps allright what's the deal with getting the signalstrength ?

[androidloverbe]

Hi,

I am unable to get the current network signal strength it does give me a value but that value is not correct (asu 99) .

TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
int event = PhoneStateListener.LISTEN_SIGNAL_STRENGTHS;
tm.listen(listenername,event);

@Override
        public void onSignalStrengthsChanged(SignalStrength signalStrength) {
            super.onSignalStrengthsChanged(signalStrength);
            signalStrength.getGsmSgnalStrength();  // asu number
            int dbm = -113 + (2 * signalStrength.getGsmSignalStrength()); // conversion to dbm
}

but it doesn't work i'm wondering why .....