How do you keep pine needles from falling off Christams Tree??

I was thinking of getting a real tree to use as a Christmas tree. It has been so many years since we had a real tree in our house that I have forgotten how it is to have one. I do remember that the pine needles were on the floor everywhere. I read somewhere that if you spray the tree with hairspray it will keep them from falling off. Anybody else heard of this?