Making Offer - tenant contingency options

[Brett C.]

Hey Investors.  I'm writing an offer ( NH property) on a two-fam with tenants in place.  I may or may not want to keep the current tenants.  How does this work in terms of contingencies in my offer?

Ideally I'd like to screen the current tenants and transfer their lease into MY lease on the day of closing if they pass my criteria.  Can I do that?  I know I can make my offer contingent on the property being empty, so why couldn't I make a contingency that says I have 10 days after the home inspection to screen and ensure the tenants will agree to my lease terms?  Or something like that.  

Ideas?