need parameter or not for method called by onClick

 XML file: Button - android:onClick="backToFirst"
 Method in java file:  public void backToFirst()

Without parameter:

 06-01 22:54:26.811: E/AndroidRuntime(421): java.lang.IllegalStateException: Could not find a method backToFirst(View) in the activity class ad01.qmn.session8.ResultActivity for onClick handler on view class android.widget.Button with id 'btnBack'

Oh, i see, it need a View  =)

How about private method or protected or the return value???
 Work:  return value
NOT Work: private, protected