error

10-29 19:19:25.377: D/AndroidRuntime(859): Shutting down VM
10-29 19:19:25.377: W/dalvikvm(859): threadid=1: thread exiting with uncaught exception (group=0x40015560)
10-29 19:19:25.397: E/AndroidRuntime(859): FATAL EXCEPTION: main
10-29 19:19:25.397: E/AndroidRuntime(859): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.rana.activities/com.rana.activities.Main}: java.lang.NullPointerException
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.ActivityThread.access$1500(ActivityThread.java:117)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.os.Handler.dispatchMessage(Handler.java:99)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.os.Looper.loop(Looper.java:123)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at java.lang.reflect.Method.invokeNative(Native Method)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at java.lang.reflect.Method.invoke(Method.java:507)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at dalvik.system.NativeStart.main(Native Method)
10-29 19:19:25.397: E/AndroidRuntime(859): Caused by: java.lang.NullPointerException
10-29 19:19:25.397: E/AndroidRuntime(859): 	at com.rana.activities.Main.onCreate(Main.java:18)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
10-29 19:19:25.397: E/AndroidRuntime(859): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
10-29 19:19:25.397: E/AndroidRuntime(859): 	... 11 more