I found an iPhone 4s and it has a passcode but I want to keep it, how do I reset it?

I don't know what the passcode is but i have an iphone but its cracked and the one i found isn't. It has a passcode on it and i don't know what it is. I was wondering if there's a way i can reset it so i can use it.

1: It is very easy to reset it. Just look it up on YouTube.
and
2: WHY in heaven's name would you keep a (expensive)smartphone that you just FOUND? My aunt left her iPhone 5 in a bathroom stall by accident and never saw it again! You people make me sick.

They can be tracked you know & if you are caught with it at the time…

Listen to Scott. You need to think twice because there have been reports of people having their phones stolen and tracking them down just to catch the perp who stole it and most of the time they sale them and it ends up on the other side of the world. If you want one so bad go buy one but report the one you have now just to save you the trouble.