崩掉了，求解
05-26 22:06:10.601: D/AndroidRuntime(3119): Shutting down VM
05-26 22:06:10.601: W/dalvikvm(3119): threadid=1: thread exiting with uncaught exception (group=0xb3aebba8)
05-26 22:06:10.621: E/AndroidRuntime(3119): FATAL EXCEPTION: main
05-26 22:06:10.621: E/AndroidRuntime(3119): Process: com.example.viewflipper, PID: 3119
05-26 22:06:10.621: E/AndroidRuntime(3119): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.viewflipper/com.example.viewflipper.MainActivity}: java.lang.ArrayIndexOutOfBoundsException: length=4; index=4
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.os.Handler.dispatchMessage(Handler.java:102)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.os.Looper.loop(Looper.java:136)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.ActivityThread.main(ActivityThread.java:5017)
05-26 22:06:10.621: E/AndroidRuntime(3119): at java.lang.reflect.Method.invokeNative(Native Method)
05-26 22:06:10.621: E/AndroidRuntime(3119): at java.lang.reflect.Method.invoke(Method.java:515)
05-26 22:06:10.621: E/AndroidRuntime(3119): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-26 22:06:10.621: E/AndroidRuntime(3119): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-26 22:06:10.621: E/AndroidRuntime(3119): at dalvik.system.NativeStart.main(Native Method)
05-26 22:06:10.621: E/AndroidRuntime(3119): Caused by: java.lang.ArrayIndexOutOfBoundsException: length=4; index=4
05-26 22:06:10.621: E/AndroidRuntime(3119): at com.example.viewflipper.MainActivity.onCreate(MainActivity.java:23)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.Activity.performCreate(Activity.java:5231)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-26 22:06:10.621: E/AndroidRuntime(3119): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-26 22:06:10.621: E/AndroidRuntime(3119): ... 11 more
