I have following code:

public class reader extends Activity {

    WebView mWebView;
    String mFilename;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mWebView = (WebView) findViewById(R.id.webView1);
        setContentView(R.layout.webview);
        mWebView.loadUrl("http://www.google.com");

     }

}

When I run this, the emulator shows "Sorry:.. mireader Stopped unexpectedly" error.. Why ? DDMS log dump: 03-02 12:25:26.430: INFO/AndroidRuntime(2837): NOTE: attach of thread 'Binder Thread #3' failed 03-02 12:25:26.729: INFO/ActivityManager(72): Start proc com.mireader for activity com.mireader/.reader: pid=2846 uid=10032 gids={3003, 1015} 03-02 12:25:29.621: DEBUG/AndroidRuntime(2846): Shutting down VM 03-02 12:25:29.621: WARN/dalvikvm(2846): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): FATAL EXCEPTION: main 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mireader/com.mireader.reader}: java.lang.NullPointerException 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.os.Handler.dispatchMessage(Handler.java:99) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.os.Looper.loop(Looper.java:123) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.ActivityThread.main(ActivityThread.java:4627) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at java.lang.reflect.Method.invokeNative(Native Method) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at java.lang.reflect.Method.invoke(Method.java:521) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at dalvik.system.NativeStart.main(Native Method) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): Caused by: java.lang.NullPointerException 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at com.mireader.reader.onCreate(reader.java:36) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 03-02 12:25:29.660: ERROR/AndroidRuntime(2846): ... 11 more 03-02 12:25:29.699: WARN/ActivityManager(72): Force finishing activity com.mireader/.reader 03-02 12:25:30.550: WARN/ActivityManager(72): Activity pause timeout for HistoryRecord{44f98868 com.mireader/.reader} 03-02 12:25:33.230: DEBUG/dalvikvm(200): GC_EXPLICIT freed 164 objects / 11312 bytes in 7516ms 03-02 12:25:35.020: INFO/Process(2846): Sending signal. PID: 2846 SIG: 9 03-02 12:25:35.080: WARN/InputManagerService(72): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@44fc35e0 03-02 12:25:35.809: INFO/ActivityManager(72): Process com.mireader (pid 2846) has died. 03-02 12:25:37.960: DEBUG/dalvikvm(320): GC_EXPLICIT freed 83 objects / 4000 bytes in 78ms 03-02 12:25:42.674: WARN/ActivityManager(72): Activity destroy timeout for HistoryRecord{44f98868 com.mireader/.reader}