nikkor 50mm 1.8d or 50mm 1.8g AF-S

Hi guys,

I am planning to get 50mm prime lens.I have nikon d7000.I would like to know if 50mm 1.8d will auto focus well with moving subjects or its simply for portraits.

or

if i should get AF-S that will have double auto focus,i quess.

I would appreciate if someone who have used both of them can provide any useful information.

AB