Como simular um click do mouse via código

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    procedure FormClick(Sender: TObject);
    procedure FormKeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure PressMouseDown(IsLeftButton: Boolean);
begin
  if IsLeftButton then
    mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0)
  else
    mouse_event(MOUSEEVENTF_RIGHTDOWN, 0, 0, 0, 0);
end;

procedure PressMouseUp(IsLeftButton: Boolean);
begin
  if IsLeftButton then
    mouse_event(MOUSEEVENTF_LEFTUP, 0, 0, 0, 0)
  else
    mouse_event(MOUSEEVENTF_RIGHTUP, 0, 0, 0, 0);
end;

procedure ClickMouseButton(IsLeftButton: Boolean);
begin
  PressMouseDown(IsLeftButton);
  PressMouseUp(IsLeftButton);
end;

procedure TForm1.FormClick(Sender: TObject);
begin
  ShowMessage('Fui clicado');
end;

procedure TForm1.FormKeyPress(Sender: TObject; 
   var Key: Char);
begin
  PressMouseDown(True);
  PressMouseUp(True);
end;

end.