hi.... i am new to android and i have been trying to create a menu....but my application stops everytime i run it on the emulator and my phone..i commented out the menu code to check whether my flipper and tab host are working and found that they are working perfectly fine ....plzz help.....Thanks in advance

.
this my MainActivity.java
package com.example.screens;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.TabHost;
import android.widget.Toast;
import android.widget.ViewFlipper;
public class MainActivity extends Activity {
TabHost th;
Button b1,b2;
private ViewFlipper ob = null;
Animation in = null , out = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
th=(TabHost) findViewById(R.id.tabhost);
th.setup();
TabHost.TabSpec spec=th.newTabSpec("tag1");
spec.setIndicator("", getResources().getDrawable(R.drawable.text));
spec.setContent(R.id.tab1);
th.addTab(spec);
spec=th.newTabSpec("tag2");
spec.setIndicator("", getResources().getDrawable(R.drawable.imageicon));
spec.setContent(R.id.tab2);
th.addTab(spec);
spec=th.newTabSpec("tag3");
spec.setIndicator("", getResources().getDrawable(R.drawable.videoicon));
spec.setContent(R.id.tab3);
th.addTab(spec);
//end of tab host code
ob = (ViewFlipper) findViewById(R.id.viewFlipper1);
b1 = (Button) findViewById(R.id.button1);
b2 = (Button) findViewById(R.id.button2);
in = AnimationUtils.loadAnimation(this,android.R.anim.fade_in);
out = AnimationUtils.loadAnimation(this,android.R.anim.fade_out);
ob.setAnimation(in);
ob.setAnimation(out);
//End of flipper code
} //End of oncreate
public void next(View v)
{
ob.showNext();
}
public void prev(View v)
{
ob.showPrevious();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.layout.activity_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId())
{
case R.id.z: Toast.makeText(this,"Moving to hair..",Toast.LENGTH_LONG).show();
return true;
case R.id.o: Toast.makeText(this,"Moving to hair..",Toast.LENGTH_LONG).show();
return true;
case R.id.t: Toast.makeText(this,"Moving to hair..",Toast.LENGTH_LONG).show();
return true;
case R.id.th: Toast.makeText(this,"Moving to hair..",Toast.LENGTH_LONG).show();
return true;
default: return super.onOptionsItemSelected(item);
}//end of switch case
}
}//End of class
AND THIS IS MY menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:id="@+id/z"
android:title="face" />
<item android:id="@+id/o"
android:title="Hair" />
<item android:id="@+id/t"
android:title="Nails" />
<item android:id="@+id/th"
android:title="Health and Nutrition" />
</menu>