unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    SysTray1: TSysTray;
    procedure Button1Click(Sender: TObject);
    procedure SysTray1IconDoubleClick(Sender: TObject;
      Button: TMouseButton; X, Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
    SysTray1.Active := True;
    Form1.Visible := False;
end;

procedure TForm1.SysTray1IconDoubleClick(Sender: TObject;
  Button: TMouseButton; X, Y: Integer);
begin
    Form1.Visible := True;
    SysTray1.Active := False;
end;

end.