Определение присутствия функции в DLL

function FuncAvail (VLibraryname, VFunctionname: string;
         var VPointer: pointer): boolean;
var
  Vlib: tHandle;
begin
  Result := false;
  VPointer := nil;
  if LoadLibrary(PChar(VLibraryname)) = 0 then
    exit;
  VPointer := GetModuleHandle(PChar(VLibraryname));
  if Vlib <> 0 then
  begin
    VPointer := GetProcAddress(Vlib, PChar(VFunctionname));
    if VPointer <> nil then
      Result := true;
  end;
end;