I am borrowing this projector from someone who does not have the manual it came with when purchased....I am flying solo trying to figure out the buttons and whistles....I have a movie screen purchased many years ago and I am trying to use it and the projector for putting together a Power Point Presentation for Sunday School class. Does anyone know how to adjust the lens so that it would fit on the movie screen. I am setting it up in a small classroom at our church. Wall to wall it may be about 30 feet by 20 feet.