unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

const
  Instructions = 'Lorem ipsum dolor sit amet, dolorum expetenda consulatu duo te, ' + sLineBreak +
    'pri stet mentitum omnesque ei, sea no rebum evertitur. Errem nonumes platonem ' + sLineBreak +
    'est ad, in admodum gubergren qui. Facilisi appellantur has ad. Erant petentium ' + sLineBreak +
    'ut nec, ius commodo eligendi iracundia te, dictas meliore reprehendunt sed eu. ' + sLineBreak +
    'Vis eius quaerendum no, id ancillae deterruisset nec.' + sLineBreak + sLineBreak +
    'Summo reprimique ne mel. Brute graeco iisque ne has, qui meliore delicatissimi ' + sLineBreak +
    'ut. Mel an iusto scripta, ut sit laboramus sententiae dissentiunt. Vis et ' + sLineBreak +
    'omnesque partiendo eloquentiam, vim principes definitiones ex, et adhuc feugait ' + sLineBreak +
    'has. Possit pericula eum ne, latine definiebas deterruisset vel eu, cum erroribus ' + sLineBreak +
    'scripserit ad. Quo populo everti oporteat ad.';

procedure TForm1.Button1Click(Sender: TObject);
begin
  // using Clear along with the Lines.Add is useless here; for how to
  // properly set the text see the Button3Click event method below
  Memo1.Clear;
  Memo1.Lines.Add(Instructions);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  // using Clear along with the Lines.Add is useless here; for how to
  // properly set the text see the Button3Click event method below
  Memo1.Clear;
  Memo1.Lines.Add(Instructions);
  Memo1.Perform(EM_SETSEL, 0, 0);
  Memo1.Perform(EM_SCROLLCARET, 0, 0);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  // instead of using Clear with the Lines.Add for adding just a single
  // string, assign it by using Text property; using this way will also
  // keep the scrollbar position on top
  Memo1.Text := Instructions;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Memo1.Width := 185;
  Memo1.Height := 89;
  Memo1.WordWrap := True;
  Memo1.ScrollBars := ssBoth;
end;

end.