User name and password

I have several network connections that I dial in to
using a modem, and I have the "Save this user name and
password" selected. If I dial into one, and then
disconnect and dial into another one, it uses the
previous user name and password, not the one that I had
set up for the current connection. It doesn't let me
save a specific user name and password for each
connection. Is there a setting I need to change or am I
doing something wrong?

Thanks!!