I want to take the value from an autonumbered field, and put that value into another table.
Example:

CREATE PROCEDURE add_customer
@FirstName varchar(50),
@LastName varchar(60),
@CompanyName varchar(100),
@EMail varchar(100),
@Address varchar(100),
@City varchar(100),
@State varchar(100),
@PostalCode varchar(20),
@Country varchar(50),
@CustomerID int OUTPUT

AS
BEGIN TRAN Add_Customer1
INSERT INTO Customer
(FirstName, LastName,EMail)
VALUES
(@FirstName, @LastName, @EMail)
SELECT @CustomerID = CustomerID FROM Customer
COMMIT TRAN Add_Customer1
GO

BEGIN TRAN Add_Customer2
INSERT INTO Customer_extra
(CustomerID, CompanyName, Address, City, State, PostalCode, Country)
VALUES
(@CustomerID, @CompanyName, @Address, @City, @State, @PostalCode, @Country)
EXEC add_customer
COMMIT TRAN Add_Customer2
GO

I get an error that I must declare the variable "CustomerID". If I omit The "GO" in the "BEGIN TRAN Add_Customer1", everything seems OK in SQL. But still I receive an error on the webpage that request the procedure. Someone that can help me with this?

remove the GO inbetween the two inserts, GO's will cancel out your variables that you have set.

The error was that I used a GO and an EXEC that I shouldn't use. I read a book and they were using Query Analyzer for their code. I wrote it in a stored procedure. That's my mistake. But now, everything works ok. Thanks!