Qwest S1 - Manual (Page 154)

140 Section 3B: Data Services
When you use data services, your user name is submitted to identify you to
the network. The user name is also useful as an address for email, as a way
to personalize Web services, and as an online virtual identity.
Your user name will be automatically programmed into your phone. You
don’t have to enter it.
Updating Your User Name
When you change the programmed user name and select a new one, you
can update your user name through your phone.
To update your user name:
ᮣ Press > Settings > Data > Update Profile.
(To cancel, press before completing the update process.)
Finding Your User Name
If you aren’t sure what your user name is, you can easily find it on your
phone.
To find your user name:
ᮣ From standby mode, press > Settings > Phone Info >
Phone#/UserID.