win32api on freepascal

I have a problem compiling this on freepascal, can you check for any error?

unit TestDll;

interface
uses Windows;
const
 NOMBREDLL = 'User32.dll';
 NOMBREFUNCION = 'GetAsyncKeyState';
// SHORT c(
  //  int vKey  // código de tecla virtual
  // );

function GetAsyncKeyState(vKey:longint):integer; *stdcall*; *external* NOMBREDLL name NOMBREFUNCION;

begin
end.