About SQL Plus prompt

In login.sql, I have added
column global_name new_value gname
set termout off
select lower(user) || '@' || name global_name from v$database
set termout on
set sqlprompt '&gname> '

But when I connect to other user in SQL PLUS, the prompt cannot be change?

manger@testing>conect test/test@testing
test@testing>

that wont re-read your login.sql unless you do @login.sql.
do do a script called connect.sql

which does
connect $1
@login.sql

where $1 is the connect string

This is fixed in 10g by the way