List user-defined error messages in SQL Server 2005

I've read a lot about defining custom error messages in SQL Server (I'm using 2005) - use sp_addmessage, pick a number over 50,000, etc. But how can开发者_JAVA百科 I query to see the custom messages that have already been defined for a database? TIA!

select * 
from sys.messages
where message_id > 50000