unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Image1: TImage;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  Image1.Picture.Icon.Handle := LoadImage( 0, IDI_WARNING, IMAGE_ICON, 0, 0, LR_DEFAULTSIZE or LR_SHARED );
  MessageDlg('mtWarning', mtWarning, [mbOk], 0);

  Image1.Picture.Icon.Handle := LoadImage( 0, IDI_ERROR, IMAGE_ICON, 0, 0, LR_DEFAULTSIZE or LR_SHARED );
  MessageDlg('mtError', mtError, [mbOk], 0);

  Image1.Picture.Icon.Handle := LoadImage( 0, IDI_INFORMATION, IMAGE_ICON, 0, 0, LR_DEFAULTSIZE or LR_SHARED );
  MessageDlg('mtInformation', mtInformation, [mbOk], 0);

  Image1.Picture.Icon.Handle := LoadImage( 0, IDI_QUESTION, IMAGE_ICON, 0, 0, LR_DEFAULTSIZE or LR_SHARED );
  MessageDlg('mtConfirmation', mtConfirmation, [mbOk], 0);
end;

end.