problema con dll

[angelp4492]

Hola como estan.
Teengo un problema al realizar una dll este es el codigo.

este es el programa


Código Delphi [-] (http://www.clubdelphi.com/foros/#)
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Label1: TLabel;
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
function GetPCName(): Pchar;stdcall; external 'CPU.dll';
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
var
c: pchar;
begin
c:=GetPCname();
label1.Caption :=c;
end;
end.





esta es la dll para obtener el nombre del pc.



library Código Delphi [-] (http://www.clubdelphi.com/foros/#)
CPU;
{ Important note about DLL memory management: ShareMem must be the
first unit in your library's USES clause AND your project's (select
Project-View Source) USES clause if your DLL exports any procedures or
functions that pass strings as parameters or function results. This
applies to all strings passed to and from your DLL--even those that
are nested in records and classes. ShareMem is the interface unit to
the BORLNDMM.DLL shared memory manager, which must be deployed along
with your DLL. To avoid using BORLNDMM.DLL, pass string information
using PChar or ShortString parameters. }
uses
windows,
SysUtils,
classes;
{$R *.res}
function GetPCName(): Pchar;stdcall;
var
PC: Pchar;
Tam: Cardinal;
begin
Tam := 100;
Getmem(PC, Tam);
GetComputerName(PC, Tam);
Result := PC;
FreeMem(PC);
end;
exports GetPCname;
begin
end
.

al ejecutar el programa me da error no me coge bien la dll o no la estoy haciendo bien
alguna idea.. gracias de antemano

[coso]

leiste lo del sharemem q pone en los comentarios?