Android TimePicker

package com.neddy;

import java.util.Calendar;

import android.app.Activity;
import android.app.Dialog;
import android.app.TimePickerDialog;
import android.app.TimePickerDialog.OnTimeSetListener;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.TimePicker;

public class HelloTimePicker extends Activity
{
    private TextView mTimeDisplay;
    private Button mPickTime;
    
    private int mHour;
    private int mMinute;
    private OnTimeSetListener mTimeSetListener=
            new OnTimeSetListener()
            {
                public void onTimeSet(TimePicker view ,int hourOfDay,int minute)
                {
                    mHour= hourOfDay;
                    mMinute=minute;
                    updateDisplay();
                }
            };
    
    static final int TIME_DIALOG_ID=0;
    
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        mTimeDisplay=(TextView)findViewById(R.id.timeDisplay);
        mPickTime=(Button)findViewById(R.id.pickTime);
        
        mPickTime.setOnClickListener(new View.OnClickListener()
        {            
            public void onClick(View v)
            {
                showDialog(TIME_DIALOG_ID);
            }
        });
        
        final Calendar c=Calendar.getInstance();
        mHour=c.get(Calendar.HOUR_OF_DAY);
        mMinute=c.get(Calendar.MINUTE);
        
        updateDisplay();
    }

    private void updateDisplay()
    {
        mTimeDisplay.setText(
                new StringBuilder()
                    .append(pad(mHour)).append(":")
                    .append(pad(mMinute)));
        
    }

    private static String pad(int c)
    {
        if(c>=10) return String.valueOf(c);
        else      return "0" + String.valueOf(c);
    }
    
    protected Dialog onCreateDialog(int id)
    {
        switch(id)
        {
            case TIME_DIALOG_ID:
            return new TimePickerDialog(this,mTimeSetListener, mHour, mMinute, false);
        }
        return null;        
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    >
<TextView
    android:id="@+id/timeDisplay"  
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text=""
    />
<Button 
    android:id="@+id/pickTime"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Change the time"
    />
</LinearLayout>