Will a Film SLR Lens work on a Digital SLR Body?

I have some Film Pentax lens (50mm, and 135mm), and i was wondering if they would work on a Nikon Digital SLR Body? D3100 is the model i was thinking of getting, if it won't work on this, will these lens work on any other Digital SLR body? I do not care much for auto focus, and these lens do not have it, will they still work with no auto focus?

On a Nikon, no unless you use an adaptor with an optical element in it which will reduce the image quality so making the exercise pointless. You should have gone for Canon or even a Pentax dSLR because they take all sorts of legacy lenses.

Cameras manufacturers design their own lens mounting systems so lenses are not interchangeable between brands.

Pentax and Nikon have the best support for older lenses on their current DSLRs. Any Pentax K K mount lens will fit and work on their latest DSLRs, and their older screw mount lenses will work using a simple adaptor.

http://aviewfinderdarkly.com.au/2007/09/12/how-to-use-old-lenses-on-a-digital-slr/

If you have Pentax lenses and want to use them consider the new Pentax K30

http://www.pentaximaging.com/dslr/K-30_Black