Change Password Form

[Susan N. Klos]

I have passwords stored in the database.  I want to create a form where the user can change the password providing of course they have the old one.  Do I need to store the old password as well as the new password in the database.  Or on the action page can I check for the old password first and exit back to the form if the old password does not match the password in the database?  If it does match go ahead and update the password in the database to the new one?