unlocking phone?

[matt 2LT]

ive been trying to unlock my old phone to give to my dad, so he can use it on o2, its currently locked to vodafone.

i bought the code off a website, and tryed typing it in, but when i put a hash in it would say inoperable character, and after pressing it a few times it then locked up.

so how do i go about getting this unlocked now?

cheers