inttohex 使用的问题，送分了啊。(50分)

下面我的button1的单击段是我从dephi的帮助里粘贴出来的，但是执行提示 there is no overloaded version of 'inttohex'that can be called with these arguments.
这是什么意思啊？我什么地方弄错了？
unit Unit1;

interface

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

type
TForm1 = class(TForm)
Button1: TButton;
Edit1: TEdit;
Label1: TLabel;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
i: Integer;
begin
Label1.Caption := '';
for i := 1 to Length(Edit1.Text) do
begin
try
Label1.Caption := Label1.Caption + IntToHex(Edit1.Text,2) + ' ';
except
Beep;
end;
end;
end;

end.

应该是帮助文档的问题把，
IntToHex(strtoint(Edit1.Text),2)旧可以了

搞定了，thanks