Ayuda con error "Variable required"

[JuanOrtega]

Tengo el siguiente codigo :

Código Delphi [-]
unit test;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var test: TFileStream;

begin

test:= TFileStream.Create( ExtractFilePath( Application.ExeName ) + 'programa.exe', fmOpenWrite );
test.Position := test.Size;

test.Write('{test}'+Edit1.Text+'{test}',1024);

test.Free;

end;

Pero cuando lo cargo me dice [DCC Error] test.pas(36): E2036 Variable required

¿ Alguien me podria explicar como lo soluciono ?