[TriLUG] PHP Question

[Mark Freeze]

I am currently working on a site hosted on Network Solutions Advanced
Unix platform that has php enabled and a limit of 2 mysql databases. 
I am going to be using both databases for different customers.  If
netsol won't let me have another database, what is the best way to
have user authentication?  My two customers will pull info from their
respective databases, but I have 5 or 10 other customers that do
nothing but upload files to me for processing.  Each different
customer would need their own username/password.  They would not have
to be able to maintain the passwords... I could set them for them. 
But, it would be nice to have a function to email them the password if
they forgot it.

Any help or suggestions will be greatly appreciated.

Regards,
Mark.