How can make AudioRecorder android

main xml
===========================================
<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />


    <Button
        android:id="@+id/button1"
        android:layout_width="125dp"
        android:layout_height="wrap_content"
        android:text="Play" />

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_below="@+id/button1"
        android:layout_marginTop="20dp"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <MediaController
            android:id="@+id/mediaController1"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
         
             >
        </MediaController>

    </LinearLayout>


    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="44dp"
        android:layout_toRightOf="@+id/button1"
        android:text="Stop" />

</RelativeLayout>

=============================================
activity class :AudioRecoderActivity .java
===================================

code :
====================

import java.io.File;
import java.io.IOException;
import android.app.Activity;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.View;
import android.view.SurfaceView;
import android.view.View.OnClickListener;
import android.widget.Button;


public class AudioRecoderActivity extends Activity {
private SurfaceHolder surfaceHolder;
private SurfaceView surfaceView;
public MediaRecorder mrec = new MediaRecorder();
private Button startRecording ;
private Button stopRecording ;
//private Button stopRecording = null;
File video;
AudioRecorder audioRecorder;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
 
    startRecording = (Button)findViewById(R.id.button1);
    stopRecording= (Button)findViewById(R.id.button2);
 
 
  /*recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
44100, AudioFormat.CHANNEL_IN_STEREO,
AudioFormat.ENCODING_PCM_16BIT, 1000);
*/
 
    audioRecorder=new AudioRecorder();
 
 
    startRecording.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {

try {
audioRecorder.start();
} catch (IOException e) {


}


}
});
 
    stopRecording.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {

try {
audioRecorder.stop();
} catch (IOException e) {


}


}
});
 
}
}

===============================================
2 nd java class :AudioRecorder
=========================




import java.io.IOException;
import java.util.Random;

import android.media.MediaRecorder;

public class AudioRecorder {

final MediaRecorder recorder = new MediaRecorder();
 public void start() throws IOException {

   recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
   recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
   recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

   int min = 1;
   int max = 999;
 
    Random r = new Random();
    int ramNum = r.nextInt(max - min + 1) + min;

    recorder.setOutputFile("/mnt/sdcard/recode_"+ramNum+".3gp");
    recorder.prepare();
    recorder.start();
 
 }


 public void stop() throws IOException {
   recorder.stop();
   recorder.release();
 }


}

===================================================================

take two permission in menifest :

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <uses-permission android:name="android.permission.RECORD_AUDIO"/>