calculator: focus on enter button

Question

Hi,

                        i have completed a calculator project. when i executed project then the contron is automatically placed on button1 so when i press enter then button1 is pressed.
                        so, how to take the control on to the enter permanently.
                        when i press another button also next the control should be on enter button .
                        so, plz answer my question.



                         Plz.... send the code.