uyguama durduruldu hatası alıyorum.

Aldığım hatayı altta belirttim. Yardımcı olursanız çok sevinirim..

06-02 06:01:42.409 8934-8934/com.fgproject.pauradyo E/AndroidRuntime: FATAL EXCEPTION: main
                                                                      Process: com.fgproject.pauradyo, PID: 8934
                                                                      java.lang.RuntimeException: Unable to start activity ComponentInfo{com.fgproject.pauradyo/com.fgproject.pauradyo.pr}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.widget.Button.findViewById(int)' on a null object reference
                                                                          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2464)
                                                                          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2524)
                                                                          at android.app.ActivityThread.access$900(ActivityThread.java:154)
                                                                          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1391)
                                                                          at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                          at android.os.Looper.loop(Looper.java:234)
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5526)
                                                                          at java.lang.reflect.Method.invoke(Native Method)
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                       Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.widget.Button.findViewById(int)' on a null object reference
                                                                          at com.fgproject.pauradyo.pr.onCreate(pr.java:29)
                                                                          at android.app.Activity.performCreate(Activity.java:6285)
                                                                          at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
                                                                          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2417)
                                                                          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2524) 
                                                                          at android.app.ActivityThread.access$900(ActivityThread.java:154) 
                                                                          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1391) 
                                                                          at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                          at android.os.Looper.loop(Looper.java:234) 
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5526) 
                                                                          at java.lang.reflect.Method.invoke(Native Method) 
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
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