Ribbon

Where do I go to buy ordinary grosgrain ribbon? I need 1" or 1 1/4" black ribbon, grosgrain or possibly velvet. I bought a dress on deep discount, $59 marked down from $179, and part of the reason it was marked down is that it has lost its belt, and even a narrow leather belt would be all wrong. Does JoAnn's even carry such a thing, or should I mail order? Mail order would be easier for me than Windsor Button, unless someone wants to do the legwork for me.

(Dress looks pretty much like this, but with a wine-colored underdress.) http://www.buzzillions.com/dz_55523_adrianna_papell_boutique_strapless_black_reviews
No, I have no idea where/when I'm going to wear it, now that Arisia is past.