如何设置打印机的横向或竖向打印？(50分)

关于打印机如何设置自定义页面尺寸，已有专家作了回答。
可我要设置横向或竖向打印，该如何做？

printer 变量有下面设置属性
property Orientation: TPrinterOrientation;


type TPrinterOrientation = (poPortrait, poLandscape);

poPortrait : 竖
poLandscape : 横

procedure TForm1.Button1Click(Sender: TObject);

begin

Printer.begin
Doc;
Printer.Canvas.TextOut(100,100,'Hi there');
Printer.EndDoc;
end;


procedure TForm1.PortraitClick(Sender: TObject);

begin

Printer.Orientation := poPortrait;
end;


procedure TForm1.LandscapeClick(Sender: TObject);

begin

Printer.Orientation := poLandscape;
end;

接受两人的答案。