Oracle Forms: How to center the windows of oracle forms

A very common issue we face that how we center our forms in Oracle Forms MDI Window. In order to track this issue, following code can be use in Form-Level Trigger WHEN-WINDOW-ACTIVATED

Declare
  v_Window Varchar2(1000) := 'MAIN';
  v_Width  Number(4);
  v_Height Number(4);
  v_MDI_Wth Number(4);
  v_MDI_Hth Number(4);
Begin
  Set_Window_Property(Forms_Mdi_Window, Window_State, Maximize);
  v_MDI_Wth := Get_Application_Property(Display_Width) - 50; 
  v_MDI_Hth := Get_Application_Property(Display_Height) - 140;

  v_Width  := Get_Window_Property(v_Window, Width);
  v_Height := Get_Window_Property(v_Window, Height);

  Set_Window_Property(v_Window,
  Position,
  (v_MDI_Wth - v_Width) / 2,
  (v_MDI_Hth - v_Height) / 2);

End;