Error Handling In An SP

hello. below is a very simple SP i have coded to insert a user into my database. i have created a unique index for the username column on my database table. if the username already i want to convey this to my C# code which is attempting the insert. i am using a combination of TRY/CATCH, RAISERROR and @@ERROR here to achieve my aim. could somebody please look at my code and tell me if the error handling code is OK, or is it overly complicated?



AS

SET NOCOUNT ON

DECLARE @Error int;

BEGIN

BEGIN TRY
INSERT INTO Users(
Username,
Password,
FirstName,
Surname,
DateBirth,
Email,
Id_Country)
VALUES(
@Username,
@Password,
@FirstName,
@Surname,
@DateBirth,
@Email,
@Id_Country)
END TRY
BEGIN CATCH

SELECT @Error = @@ERROR;

IF @Error = 2601
RAISERROR('The username already exists.', 15, 1)
ELSE
RAISERROR('An unknown error occurred.', 15, 1)

RETURN @Error;

END CATCH

SELECT @Id_User = SCOPE_IDENTITY()

END