You can reset the default values
at a later time. In this example, 
dbname is the name of the database for
which you are enabling RepAgent, 
repserver_name is
the Replication Server to which RepAgent connects, and 
repserver_username and 
repserver_password are
the name and password RepAgent uses to log in to Replication Server.
Note: Make sure that repserver_username is
a valid Replication Server user and that it has Replication Server connect
source permission. Try out the user name and password
at the Replication Server before you use sp_config_rep_agent.