old iphone 5 and know its ask me to for my old email address and password

Hey everybody, here the problem I have a iphone5 that been laying around the house. so I decide before I let my kids use it like a mini ipad tablet just using the wiffi in the home. I would just restore it to the factor settings, and now its asking me for my old email account and the old password that I used to set up the phone when I first got it two years ago. So what do I do now to get this phone unlock? and I did try looking up my old email on apple web site and it say there nothing here with that name.