Yeah this is a noob question, but I am still going to ask it. I have a nikon d40x body. I know that the AF motor must be in the lens itself. I am looking at this lens, but the nikon site does not have much info. http://www.nikonusa.com/template.php?cat=1&grp=5&productNr=1963# Will this work on my body? Will the AF work or will I just have to utilize manual focus only? Thanks for the halp!