launching a new activity in Android -

i trying learn screen navigation in android 

i trying achieve follows

• when click on button in activity launches new activity
• but end activity must contain button when on click should return first activity

ill post descriptive code below

copperchimneydesc.java

@override protected void oncreate(bundle savedinstancestate) {     // todo auto-generated method stub     super.oncreate(savedinstancestate);     setcontentview(r.layout.copperchimney_desc_screen);   button photobutton=(button) findviewbyid(r.id.copperchimneyphotosbutton);             photobutton.setonclicklistener(new onclicklistener() {                  @override                 public void onclick(view v) {                     // todo auto-generated method stub                     intent pht=new intent(copperchimneydesc.this,copperchimneyphotos.class);                     startactivity(pht);                  }             }); 

copperchimneyphotos.java

public class copperchimneyphotos extends activity{      @override     protected void oncreate(bundle savedinstancestate) {         // todo auto-generated method stub         super.oncreate(savedinstancestate);          setcontentview(r.layout.copper_chimney_photos);           button btn=(button) findviewbyid(r.id.photobutton);          btn.setonclicklistener(new onclicklistener() {              @override             public void onclick(view v) {                 // todo auto-generated method stub                 intent pt=new intent(copperchimneyphotos.this,copperchimneydesc.class);                 startactivity(pt);             }         });     } 

ps:: have declared new activity in manifest

my error log follows::

08-16 17:42:33.730: e/androidruntime(444): fatal exception: main 08-16 17:42:33.730: e/androidruntime(444): java.lang.runtimeexception: unable start activity componentinfo{com.project.findmybuffet/com.project.findmybuffet.copperchimneydesc}: java.lang.nullpointerexception 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.activitythread.performlaunchactivity(activitythread.java:1647) 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.activitythread.handlelaunchactivity(activitythread.java:1663) 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.activitythread.access$1500(activitythread.java:117) 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.activitythread$h.handlemessage(activitythread.java:931) 08-16 17:42:33.730: e/androidruntime(444):  @ android.os.handler.dispatchmessage(handler.java:99) 08-16 17:42:33.730: e/androidruntime(444):  @ android.os.looper.loop(looper.java:123) 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.activitythread.main(activitythread.java:3683) 08-16 17:42:33.730: e/androidruntime(444):  @ java.lang.reflect.method.invokenative(native method) 08-16 17:42:33.730: e/androidruntime(444):  @ java.lang.reflect.method.invoke(method.java:507) 08-16 17:42:33.730: e/androidruntime(444):  @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:839) 08-16 17:42:33.730: e/androidruntime(444):  @ com.android.internal.os.zygoteinit.main(zygoteinit.java:597) 08-16 17:42:33.730: e/androidruntime(444):  @ dalvik.system.nativestart.main(native method) 08-16 17:42:33.730: e/androidruntime(444): caused by: java.lang.nullpointerexception 08-16 17:42:33.730: e/androidruntime(444):  @ com.project.findmybuffet.copperchimneydesc.oncreate(copperchimneydesc.java:39) 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1047) 08-16 17:42:33.730: e/androidruntime(444):  @ android.app.activitythread.performlaunchactivity(activitythread.java:1611) 08-16 17:42:33.730: e/androidruntime(444):  ... 11 more 

any ideas on how overcome this, have pasted relevent code .

you call finish() method..

btn.setonclicklistener(new onclicklistener() {

        @override         public void onclick(view v) {              finish();         }     }); 

in second activity