won't hold curls!

I had my hair all rolled up from about 6pm yesterday, all nite...took the rollers out this morning and it was all curly...

Now it's 1:15 pm...I've been inside sitting at my desk all day and just went to the rest room, looked in the mirror and my curls are almost gone...

I wish I had done before and after pics so you could see...

Hmmmm..so what can I do to make my curls last longer? : (