Microsoft SQL function code example to pull Syteline invoice tax.

USE [testsite_live_App]
GO
/****** Object: UserDefinedFunction [MYSCHEMA].[_chad_EDI_get_invoice_tax]    Script Date: 06/24/2013 23:38:36 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION [MYSCHEMA].[_chad_EDI_get_invoice_tax] (
@INV_NUM nvarchar(12))
RETURNS AmountType
AS
BEGIN
   RETURN   (SELECT SUM(sales_tax)
                  FROM inv_stax
                  WHERE inv_num = @INV_NUM)

END