Will my pay as you go sim work in a Blackberry storm 9500?

[M3l93]

My friend is selling his Blackberry Storm 9500, and i'm thinking of buying it. He is on Vodafone and im on O2, so he said that he would get it unlocked, so that shouldnt be a problem. The only problem that i have is that my sim card is a pay as you go and he was on a contract. Do any of you know if my sim card will work in this new phone or not because i dont want to buy it if it wont work?! Any answers appreciated. Thanks