Question : SQL Server Authentication

In my spare time I am creating a small VB.net winforms application to be distributed as a commercial package with SQL Server Express as the back-end database.   I tried (mostly from habit because I use Oracle authentication for users at my job) to use SQL Server authentication but my (made-up) user id and password failed, so I went to Windows Authentication and had not trouble.   I am not sure which mode I should be using, or what more I needed to know/do to use SQL Server Authentication.   Advice, suggestions, appreciated.  Thanks in advance.

Answer : SQL Server Authentication

by default sql server authentication is disabled in express edition
you must enable it by this:
go to :
start
programs
microsoft sql server 2005 or 2008
sql server management studio
connect to your express edition with windows authentication
then it appears in right panel as object explorer
right click on server name
go to properties
in security tab select sql server authentication mode

you must also specify password for sa user this is sql server adiministrator
so go to security and logins, and enable this user too

remember you must restart sql server express after this changes