How to know if a user's password is expired when login to InfoView?

Hi,

I'm trying to develop an sso application in jsp. When my users log in, I need to check if their password are expired or not.

I've tried the IUserInfo.getPasswordExpiry method, but I don't know if it is the right method to use.
It always returns the value "3650", what ever setting I set in the Authentication section of the CMC.

How do you check if a password has expired?

Thanks.