Ring Tone Play and Snooz dialog

package com.example.spinnerapp;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {
private static final String SHAREDPREFERENCES = "sp";
private static final String RINGTONEPOS = null;
protected static final String RINGTONE = null;
Dialog mAlertDialog;
private static final String SNOOZETIMEPOS="keySnoozeTimePos";
private static final String SNOOZETIME="keySnoozeTime";
private Button btn1,btn2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

btn1 = (Button)findViewById(R.id.btn1);
btn1.setOnClickListener(this);
btn2 = (Button)findViewById(R.id.btn2);
btn2.setOnClickListener(this);

}
    private void StopMusic()
    {
    if(mMediaPlayer!=null)
{
if(mMediaPlayer.isPlaying()==true)
{
mMediaPlayer.release();
mMediaPlayer=null;
}
}
    }
//This Is For Play Music
    private void PlayMusic() {
    mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
    //mMediaPlayer.setLooping(true);
   mMediaPlayer.start();
// i.e. react on the end of the music-file:
// mMediaPlayer.setOnCompletionListener(new OnCompletionListener(){
//
// // @Override
// public void onCompletion(MediaPlayer arg0) {
// System.out.println("Songs Finish");
// }
// });
}
   
   
    @Override
    protected void onPause() {
    super.onPause();
    StopMusic();
    }
    int ringpos=0;
    private MediaPlayer mMediaPlayer=null;
private void Ringtoneset()
{
      final int[] ringtoneid={R.raw.a,R.raw.b,R.raw.c};
           final CharSequence[] ringtoneitems = {"Arctic","Extream","Going Solo"};
  SharedPreferences mSPreferences=getSharedPreferences(SHAREDPREFERENCES,Context.MODE_WORLD_READABLE);
       ringpos = mSPreferences.getInt(RINGTONEPOS,0);
       AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
       builder.setTitle("Ringtones Set");
   
       builder.setSingleChoiceItems(ringtoneitems, ringpos, new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int item) {
           //    Toast.makeText(Setting.this, ringtoneitems[item], Toast.LENGTH_SHORT).show();
            ringpos=item;
            StopMusic();
            mMediaPlayer = MediaPlayer.create(MainActivity.this,ringtoneid[item]);
            PlayMusic();
           }
       });
     
       builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
               SharedPreferences mSharedPreferences=getSharedPreferences(SHAREDPREFERENCES,MODE_WORLD_WRITEABLE);
            SharedPreferences.Editor mEditor=mSharedPreferences.edit();
            mEditor.putInt(RINGTONE, ringtoneid[ringpos]);
            mEditor.putInt(RINGTONEPOS, ringpos);
            mEditor.commit();
            Toast.makeText(MainActivity.this, ringtoneitems[ringpos], Toast.LENGTH_SHORT).show();
            StopMusic();
             
mAlertDialog.dismiss();
                }
            });
       builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int whichButton) {
                StopMusic();
                mAlertDialog.dismiss();
               }
       });
       mAlertDialog = builder.create();
       mAlertDialog.setCancelable(false);
       mAlertDialog.show();
}

private AlertDialog mAlertDialog1 = null ;
private void Snoozeset()
{
   final int[] snoozetime={10,15,20};
       final CharSequence[] snoozeitems = {"10 Minutes", "15 Minutes", "20 Minutes"};
//        final int[] snoozetime={2,3,4};
//        final CharSequence[] snoozeitems = {"2 Minutes", "3 Minutes", "4 Minutes"};
     
       SharedPreferences mSPreferences=getSharedPreferences(SHAREDPREFERENCES,Context.MODE_WORLD_READABLE);
       int pos = mSPreferences.getInt(SNOOZETIMEPOS,0);
       AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
       builder.setTitle("Snooze Minutes");
       builder.setSingleChoiceItems(snoozeitems, pos, new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int item) {
          //     Toast.makeText(Setting.this, snoozeitems[item], Toast.LENGTH_SHORT).show();
               SharedPreferences mSharedPreferences=getSharedPreferences(SHAREDPREFERENCES,MODE_WORLD_WRITEABLE);
            SharedPreferences.Editor mEditor=mSharedPreferences.edit();
            mEditor.putInt(SNOOZETIME, snoozetime[item]);
            mEditor.putInt(SNOOZETIMEPOS, item);
            mEditor.commit();
            btn2.setText(snoozeitems[item].toString());
               mAlertDialog.dismiss();
           }
       });
       builder.setNegativeButton(android.R.string.cancel,
               new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int whichButton) {
                mAlertDialog.dismiss();
               }
       });

       mAlertDialog = builder.create();
       mAlertDialog.setCancelable(true);
       mAlertDialog.show();
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(v==btn1){
Snoozeset();
}else if(v==btn2){
Ringtoneset();
}
}


}