Which edit selected?

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Edit2: TEdit;
    Button2: TButton;
    Timer1: TTimer;
    Panel1: TPanel;
    Edit3: TEdit;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    procedure SelectedEditEnter(Sender: TObject);
    procedure SelectedEditExit(Sender: TObject);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
  SelectedEdit: TEdit = nil;

procedure TForm1.SelectedEditEnter(Sender: TObject);
begin
  SelectedEdit := (Sender as TEdit);
end;

procedure TForm1.SelectedEditExit(Sender: TObject);
begin
  SelectedEdit := nil;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  i: Integer;
begin
  for i := 0 to Pred(ComponentCount) do
    if Components[i].ClassName = 'TEdit' then
    begin
      (Components[i] as TEdit).OnEnter := SelectedEditEnter;
      (Components[i] as TEdit).OnExit := SelectedEditExit;
    end;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  if Assigned(SelectedEdit) then
    Caption := SelectedEdit.Name
  else
    Caption := '';
end;

end.