Can anyone recommend a scope for an AR-15? I want it just for fun, so I would prefer not to spend more than $100 or so, but I would like to be able to see a target that is 100 yards away. I have seen a Leapers tactical scope on firequest.com for less than $100, but I confess that I know so little about scopes I am not sure what to look for. My AR-15 is a Colt that has the carry handle on top. Thanks for any recommendations.