eclipse 虚拟机无法使用编写的应用程序的menu

//按书上做的
//以下为FirstActivity.java
package com.test.activitytest;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.Toast;

public class FirstActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.first_layout);
    Button button1 = (Button) findViewById(R.id.button_1);
    button1.setOnClickListener(new OnClickListener()
    {
        @Override 
        public void onClick(View v)
        {
            Toast.makeText(FirstActivity.this, "you clicked Button 1", 
                    Toast.LENGTH_SHORT).show();
        }
    });

}

public boolean onCreateOptionMenu(Menu menu)
{
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}
public boolean onOptionsItemSelected(MenuItem item)
{
    switch (item.getItemId()){
    case R.id.add_item:
        Toast.makeText(this, "You clicked Add", Toast.LENGTH_LONG).show();
        break;
    case R.id.remove_item:
        Toast.makeText(this, "You clicked Remove", Toast.LENGTH_SHORT).show();
        break;
    default:
    }
    return true;
}

}
//以下为menu/main.xml
<?xml version="1.0" encoding="utf-8"?>

android:id="@+id/add_item"
android:title="@string/menu_add"
/>
android:id="@+id/remove_item"
android:title="@string/menu_remove"
/>

//以下为 values/string.xml

<string name="app_name">ActivityTest</string>
<string name="message">Button 1</string>
<string name="menu_add">Add</string>
<string name="menu_remove">Remove</string> 

写菜单程序只有上面这三个文件

运行了之后没有错误，但是打开虚拟机中的应用程序，然后按menu键没有菜单弹出
初学，求大神指教

以上和你原来代码是一样的吧？
很简单，你没有覆盖菜单事件，没加@override啊