procedure TForm1.Button1Click(Sender: TObject);
function FuncAvail
(_dllname, _funcname: string; var _p: pointer):
boolean;
var _lib: tHandle;
begin
Result := false;
_p := NIL;
if LoadLibrary(PChar(_dllname)) = 0 then exit;
_lib := GetModuleHandle(PChar(_dllname));
if _lib <> 0 then
begin
_p := GetProcAddress(_lib, PChar(_funcname));
if _p <> NIL then Result := true;
end;
end;
var
xBlockInput : function(Block: BOOL):
BOOL; stdcall;
begin
if FuncAvail
('USER32.DLL', 'BlockInput', @xBlockInput) then
begin
xBlockInput(true);
Sleep(5000);
xBlockInput(false);
end;
end;
Tapi cuman bisa dalam 5 detik saja, jika ingin lebih lama silahkan diubah 5000 nya.... :D