I need a way to keep my strapless Prom dress from slipping down so I don't have to pull on it all night.?

I have a strapless prom dress this year and although it fits me almost perfectly the top isn't quite snug enough. It is manageable but I'm wondering if there is anything that I can do to reduce the times I have to pull it up. I want it to be romantic...not trashy. My prom is tomorrow so I really don't have time to get it taken in or order anything. Any ideas?