Need clean windows?

My windows, especially the French doors, have this film on them and I haven't been able to get rid of it. I have washed and washed and they look terrible, so yesterday I searched cyberspace and found a recipe for window wash. I mixed 2 cups of water and 1/4 cup white distilled vinegar and 1/2 teaspoon of dish soap. It worked like a charm. I found out that Windex and similar cleaners leave a waxy residue and you need the dish soap to cut through it. Now if my boys could just keep their greasy paws off of the glass...