Error showing "unfortunatey the app has stopped working" in Android -

i trying make app in android when m trying run app in mobile phone, whenever click on button says "unfortunately app has stopped working", here code, can tell me m u doing wrong here

import android.support.v7.app.actionbaractivity; import android.os.bundle; import android.view.menu; import android.view.menuitem; import android.view.view; import android.widget.button; import android.widget.edittext;   public class mainactivity extends actionbaractivity {  edittext titleedittext; edittext noteedittext; @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      final button savebutton = (button)findviewbyid(r.id.button);     savebutton.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {              titleedittext = (edittext)findviewbyid(r.id.title);              noteedittext = (edittext)findviewbyid(r.id.note);             titleedittext.setenabled(false);             noteedittext.setenabled(false);         //savebutton.settext("clicked!");         }     }); } 

`

put these 2 lines out of onclick listener , change note id of edittext in xml file small letters should 'note'.

titleedittext = (edittext)findviewbyid(r.id.title);  noteedittext = (edittext)findviewbyid(r.id.note);