At this point, all of the necessary work has been done to establish the base of your project. Then create a table and procedure to hold and query users and passwords. For this example, I used the following:

Authentication.sql
**************************************************

1:    CREATE TABLE [dbo].[User] (
2:    username char(25),
3:    password char(25),
4:    )
5:    
6:    
7:    CREATE PROCEDURE MyAuthentication
8:    
9:    (
10:   @username Char( 25 ),
11:   @password Char( 25 )
12:   )
13:   As
14:   
15:   DECLARE @actualPassword Char( 25 )
16:   
17:   SELECT
18:   @actualPassword = Password
19:   FROM [Users]
20:   Where username = @username
21:   
22:   IF @actualPassword IS NOT NULL
23:   IF @password = @actualPassword
24:   RETURN 1
25:   ELSE
26:   RETURN -2
27:   ELSE
28:   RETURN -1
29:   GO

The table called users holds the username and passwords of visitors. The procedure called MyAuthentication is the gateway to the table users. It allows 2 parameters to be passed, username and password. The procedure then queries the table for entries where the passed username (@username) is equal to the username in the table (username). The If..Else statement works similar to any other programming if..else statement. If no results are returned from the select statement, the procedure will return a -1. If results are returned, the next If..Else statement is executed. This statement checks to see if the passed password (@password) is equal to the actual password in the table (@actualPassword). If it is, 1 is returned. Otherwise, a -2 will be returned.