Show level battery (Android)

package com.battery.alarm;

import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends Activity {
    private TextView contentTxt , Txt;
    private BroadcastReceiver mBatInfoReceiver = new BroadcastReceiver(){
        @Override
        public void onReceive(Context arg0, Intent intent) {
          int level = intent.getIntExtra("level", 0);
          contentTxt.setText(String.valueOf(level) + "%");
          if(level > 49)
              Txt.setText("High");
          else
              Txt.setText("Lol");
        }
      };
      @Override
      public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.activity_main);
        contentTxt = (TextView) this.findViewById(R.id.textView1);
        Txt = (TextView) this.findViewById(R.id.textView2);
        this.registerReceiver(this.mBatInfoReceiver,
        new IntentFilter(Intent.ACTION_BATTERY_CHANGED));

      }
}