unit  Unit1;

 interface 

 uses 
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

 type 
  TForm1 =  class (TForm)
    Edit1: TEdit;
    Edit2: TEdit;
     procedure  Edit1Exit(Sender: TObject);
     procedure  Edit2Enter(Sender: TObject);
   private      { Private declarations } 
   public       { Public declarations } 
   end ;

 var 
  Form1: TForm1;

 implementation 

 var 
  LastFocusedControl: TWinControl;

 {$R *.dfm} 

 procedure  TForm1.Edit1Exit(Sender: TObject);
 begin 
  LastFocusedControl := TWinControl(Sender);
 end ;

 procedure  TForm1.Edit2Enter(Sender: TObject);
 begin 
  FocusControl(LastFocusedControl);
 end ;

 end .