Forms security on db side

Hi Friends,

How do I make our 3rd party appl forms login more secure?

Currently, the appl program uses a primitive database authentication method
by providing the username and password of the database in clear text inside
a .ini file. Changing the database user and password will be useless due to
password being exposed literally. Users of the application are registered in a table in the database with the password of the user exposed in clear text. An administrator or anybody with database access will be able see a user's password in clear text thus user authentication is compromised.

Can I change the username to point to the database username and not a table?
Can I incrypt the password table entry itself?
Can I incrypt the .ini file so as not to show literal passwords?
Can I use the form to get the userid/passwd from LDAP active directory server?

Please help ....thanks a lot