I am looking to achieve similar results to this post  but I cannot get my SQL statement to function properly.  Per Robert's instruction, I am creating a IF clause in my SQL Statement, but for whatever reason it is triggering when the form loads AND when the field notused is changed.  Below is my sql statement and screenshots from my form.  Any help is much appreciated!  

	   USE [LFForms]
GO
/****** Object:  StoredProcedure [dbo].[sp_increment]    Script Date: 9/30/2015 9:15:06 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
       ALTER PROCEDURE [dbo].[sp_increment]
	   (
	   @notused varchar(50) output
	   )
       AS
	  
	   BEGIN
	   
	   Declare @myvalue int
	   
       select @myvalue= [RequestNumber] from dbo.RequestNumber where name = 'access'
	   IF @notused is NOT NULL
	   BEGIN
       update dbo.RequestNumber set [RequestNumber] = @myvalue + 1 where name = 'access'
       Declare @myTable table
       (
       [RequestNumber] nvarchar(50)
       )
       INSERT INTO @myTable ([RequestNumber]) values (@myvalue)
       select top 1 * from @mytable
	   RETURN @myvalue
	   END
	   ELSE BEGIN
	   RETURN @notused
	   END
	   END

Cheers!  

Nate