How to find the authentication methord used

This script will help you find the authentication method of logins in sql 2005.

SELECT 'Authentication Method'=(
CASE
WHEN nt_user_name IS not null THEN 'Windows Authentication'
ELSE 'SQL Authentication'
END),
login_name AS 'Login Name', ISNULL(nt_user_name,'-') AS 'Windows Login Name',
COUNT(session_id) AS 'Session Count'
FROM sys.dm_exec_sessions
GROUP BY login_name,nt_user_name