Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: I have old lenses for a Nikon 801 (zoom up to 300 AF). Does them fix in D3100? And if I can use AF function of this lenses in this D3100?? thanks
Document: I have used a simple point and shoot digital camera for years. I have an old Nikon 35mm with lenses and all but when it became impossible to get film I went to a point and shoot.I have been eyeing this camera for a few years and finally got one.I was not disappointed. This takes great pictures. Very clear and tack sharp.I like the ruby color as its a great change from the basic black.I recommend this camera for all beginners and amateurs.
My first real decent digital camera.I am loving it.Thought it would be a bit intimidating but is pretty self explanatory & has been(so far)easy to use.Love the pictures it's taken & also takes video.Great to use for travel or for every day family & friend pictures.
It's very easy to use once you get a good idea about what you're doing with it. The red color is very pretty too.I liked that this offered a video option but at this point I have yet to capture a decent video on it... I recently messed with some settings so it might be better now, but I haven't checked. Prior to changing settings, my iPhone took better video.
I've been wanting this camera for a long time now and now I have it in my hands!The camera takes a while to get use to, but once you get use to it, it works great! It can record videos great too! The mic filters out a lot or most of the ambiance, but you can still a strange humming still, though that isn't a big deal. Everything is still really clear.It is very easy to use and very light in weight.
So I say buy and learn. You will love the pictures you can capture with this camera. The body is easy to hold and the lenses go on and off with ease. So get yourself this camera and head out to grab some great shots! !
I have Been a hobby photographer for the last 25 years and a professional for the last 3 years, and the D3100 has a great array of all of the professional (options) to fine tune the perfect shot with Active D-Lighting (d=dynamic) it literally shoots with active d lighting or can be edited with D-Lighting in the camera pre transfer.
I saw this camera on a cruise ship (photography shop was selling them), however it was $150.00 more than what I found on Amazon. It has excellent picture quality and all of the features you would expect. I did also purchase the more powerful lens as I travel extensively all over the world for pleasure and need both lenses. A great SLR for the price.
My only Must have with a D3100 is a SDHC memory card with a rating of 8-10 for the 1080 HD video and a tripod. and when using the camera for video leave it on the tripod !! if in video mode it can have a wabbly look if it is panned to fast or moved a bit too quickly !!
Awesome camera. It is user friendly. I bought it for my daughter who has never used anything but a camera on a phone.
Just got this at best buy for $349. Same kit, same lens, same camera. I also added a two year geek squad warranty for $60.
Answer: These older Nikon lenses are optically ok and will fit you D3100 but they won't let you autofocus. Only Nikon AF-S and G-series lenses will autofocus on a D3100. These lenses can be used on any D-SLR which has a focus motor. The D3100 does NOT have the focus motor so your lense will not work.  However you can try using it in Manual mode but I have never had much luck with this. I hope this helps.