我是新手，请问各位大哥些 下面的代码为什么

CSPOK

unit Unit1;

interface

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

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

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
var a,b:integer;
var c,d:cardinal;
begin
c :=$efab1234 ;
a :=c;
b :=-(not c+1);
d :=-(not c+1);
if a=b then
showmessage('a=b,'+inttostr(a));
if a <> c then
showmessage('a('+inttostr(a)=')<>c('+inttostr(c)+')');
if c=d then
showmessage('c=d,'+inttostr(c));
end;

end.


在DELPHI7中运行不了，该怎么改？谢谢各位了