Thread: error when switch activity in android

hai, i am new in android and android game is my first project. i am having problem with switching activity. my project contains 3 activities and 3 layout. there's no error in console but the application can't be run and the emulator says: "The Application TamaDroid (process tamagochi.app) has stopped unexpectedly. Please try again"
i am using android emulator 2.3 and API 9.

here is the code:

tamagochi.java

public class tamagochi extends ListActivity {
 
	public void onCreate(Bundle savedInstanceState) {
	     super.onCreate(savedInstanceState);
	     setContentView(R.layout.tamagochi_layout);
 
	     Button loginButton = (Button) findViewById(R.id.login);
	     loginButton.setOnClickListener(new View.OnClickListener() {
	             public void onClick(View view) {
	                 Intent myIntent = new Intent(view.getContext(), login.class);
	                 startActivityForResult(myIntent, 0);
	             }
 
	     });
 
	     Button joinButton = (Button) findViewById(R.id.join);
	     joinButton.setOnClickListener(new View.OnClickListener() {
	             public void onClick(View view) {
	                 Intent myIntent = new Intent(view.getContext(), register.class);
	                 startActivityForResult(myIntent, 0);
	             }
 
	     });
 
	     Button exitButton = (Button) findViewById(R.id.exit);
	     exitButton.setOnClickListener(new View.OnClickListener() {
	             public void onClick(View view) {
	                 System.exit(0);
	             }
 
	     });
	}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="tamagochi.app"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".tamagochi"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".choosepet"></activity>
		<activity android:name=".login"></activity>
		<activity android:name=".petMain"></activity>
		<activity android:name=".register"></activity>
    </application>
    <uses-sdk android:minSdkVersion="9" />
</manifest>

and here is the screenshot of error:

error.android.JPG

and here is the error in logcat

10-24 11:41:08.006: ERROR/AndroidRuntime(644): FATAL EXCEPTION: main
10-24 11:41:08.006: ERROR/AndroidRuntime(644): java.lang.RuntimeException: Unable to start activity ComponentInfo{tamagochi.app/tamagochi.app.tamagochi}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ActivityThread.performLaunchActivity(A ctivityThread.java:1622)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ActivityThread.handleLaunchActivity(Ac tivityThread.java:1638)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ActivityThread.access$1500(ActivityThr ead.java:117)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ActivityThread$H.handleMessage(Activit yThread.java:928)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.os.Handler.dispatchMessage(Handler.java:99 )
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.os.Looper.loop(Looper.java:123)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ActivityThread.main(ActivityThread.jav a:3647)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at java.lang.reflect.Method.invokeNative(Native Method)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at java.lang.reflect.Method.invoke(Method.java:507)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:839)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:597)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at dalvik.system.NativeStart.main(Native Method)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ListActivity.onContentChanged(ListActi vity.java:243)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at com.android.internal.policy.impl.PhoneWindow.setCo ntentView(PhoneWindow.java:210)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.Activity.setContentView(Activity.java: 1657)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at tamagochi.app.tamagochi.onCreate(tamagochi.java:18 )
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.Instrumentation.callActivityOnCreate(I nstrumentation.java:1047)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): at android.app.ActivityThread.performLaunchActivity(A ctivityThread.java:1586)
10-24 11:41:08.006: ERROR/AndroidRuntime(644): ... 11 more

please help me, i am counting on your help. thank you..