SQL Server 2008 Stored Procedure with multiple output parameters

I have a stored procedure as follows:

ALTER PROCEDURE [dbo].[sp_web_orders_insert]
(
    @userId int = default,
    @custId int = default,
    @orderDate datetime = default,
    @orderTotal money = default,
    @statusId int = default,
    @orderReference varchar(50) = default,
    @custReference varchar(50) = default,
    @order_ID INT output,
    @orderReferenceOutput varchar(50) output
)
AS


    SET NOCOUNT OFF;
    INSERT INTO [web_orders] ([user_ID], [cust_ID], [orderDate], [orderTotal], [statusId], [orderReference], [custReference]) VALUES (@userId, @custId, @orderDate, @orderTotal, @statusId , 'PLC' + REPLICATE('0', (7 - LEN((select MAX(order_ID) from web_orders)))) +  CAST((select(max(order_ID)+1) from web_orders) AS VARCHAR(5)), @custReference);

    SELECT @order_ID = @@IDENTITY
    RETURN @order_ID

    SELECT @orderReferenceOutput = 'PLC' + REPLICATE('0', (7 - LEN((select MAX(order_ID) from web_orders)))) +  CAST((select(max(order_ID)+1) from web_orders) AS VARCHAR(5))
    RETURN @orderReferenceOutput 

For some reason the second output parameter @orderReferenceOutput returns nothing. The purpose of this second output parameter is to retrieve a column I have just inserted into the database.