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

var
  Form1: TForm1;

implementation
{$R *.DFM}
Procedure DoRevertStr(Str:PChar); stdcall;
                                                   external 'MYLIB.DLL';

Function SumXY(x,y:integer):integer; stdcall;
                                                   external 'MYLIB.DLL';

Function SubtractXY(x,y:integer):integer; stdcall;
                                                   external 'MYLIB.DLL';


procedure TForm1.Button1Click(Sender: TObject);
begin
   DoRevertStr('Hello World');

   ShowMessage('Here is SumXY result:'
                                                +IntToStr(SumXY(1,3)));
   ShowMessage('Here is SubtractXY result:'
                                                +IntToStr(SubtractXY(1,3)));
end;
