How to create a user account with the same permission as "root" ?

[williamkow]

Finally, I manage to setup X.org and then KDE 3.5.4 running on FreeBSD 
6.2-Release.
I created a user account named "william" and do not assign any group as 
I do not know what are the list of group name for me to select. To start 
KDE, i use command "kdm" but I can only logon using the newly created 
user name "william", but it do not have same permission/access rights as 
"root" account.
Please show on how to enable this user account, with the same permission 
as root ?
Thank you.