Cant make a Gallery


I hope someone can help me.
Well, its not for me, but for two friends.

I have made my gallery and it works great, but my friends (they both uni, and have pics and videos to upload) cant make theirs!

I have the username and password for one of them.
When you go on the gallery, and try and log in, it wont work. It says ‘Error: Invalid username or password’

Can someone help us please.