public void Update()  
         {
             state = Keyboard.GetState();

             if (state.IsKeyDown(Keys.Space) && oldState.IsKeyUp(Keys.Space))
                 s_items[currItem].OnClick();

             int delta = 0;
             if (state.IsKeyDown(Keys.Up) && oldState.IsKeyUp(Keys.Up))
                 delta = -1;

             if (state.IsKeyDown(Keys.Down) && oldState.IsKeyUp(Keys.Down))
                 delta = 1;

             currItem += delta;
             bool ok = false;
             while (!ok)
             {
                 if (currItem < 0)
                     currItem = s_items.Count - 1;
                 else if (currItem > s_items.Count - 1)
                     currItem = 0;
                 else if (s_items[currItem].active == false)
                     currItem += delta;
                 else ok = true;
             }
             oldState = state;
         }