stage 4 finishing the user interface i have to errors what i'am doing wrong

./LandingActivity.java:23: error: cannot find symbol
            int nextPage = mCurrentPage.mRelaunchButton().getNextPage();
                           ^
  symbol: variable mCurrentPage
./LandingActivity.java:24: error: cannot find symbol
              loadPage(nextPage);

```LandingActivity.java
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class LandingActivity extends Activity {

    public Button mRelaunchButton;

    // Some previous code omitted for brevity

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_landing);

        // Some previous code omitted for brevity

        mRelaunchButton = (Button)findViewById(R.id.relaunchButton);
        mRelaunchButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // Add your code here!
            int nextPage = mCurrentPage.mRelaunchButton().getNextPage();
              loadPage(nextPage);
              finish();


            }
        });
    }
}