Im trying to compile a DLL to use with mIRC (chat client with an integrated language)

library dll;

uses
    SysUtils,
    Classes,
    Windows;

function Test(mWnd, aWnd : HWND; data, parms : PChar; show, nopause : boolean) : integer; stdcall;
var
   s : string;
begin
     s := 'Hello World';
     strcopy(data, PChar(s));
     result := 3;
end;

begin
end.

exports Test;

Compiler: Dev-Pascal 1.9.2

Im getting one error:
- Fatal: Can't find unit CLASSES

I can compile if i remove Classes, but then i can't access the function im trying to export (Test)

Can anyone suggest a solution?

Im surprised that classes would stop you seeing the exported function, but then Im not up on dev-pascal.