My daughter forgot her iphone 4 password. Its locked up. What do we do?

She was playing around with it and the phone locked up.
IT is the iphone 4

thanks

Added (1). I guess she needs a password reset or restore.

If re setting the phone doesn't work, you might have to take it to the store and get them to reset it.
It happened to me before but not with the iphone, and I had to take it to the store to get it reset

If you plug your phone into the computer that you are using itunes with for that phone you should be able to unlock it.

Plug it into the computer, then restore it.