Excel 2007 : standard deviation

How would I be able to recalculate the standard deviation automatically if I filter by Name1 or Name2.

So for example, if I filter by Name 2 by Brown, I want only the items that are filter by Name 2.

So the standard deviation for Item B should be 52 and not 47.9 when Brown is filter.

I would assume you use subtotal and your function above but I can't get it to work