>I created a user function to handle this.
>
>

>CREATE FUNCTION [dbo].[isIN] 
>(
>	@lcStr varchar(100) ,
>	@lcList varchar(max)
>)
>RETURNS int 
>AS
>BEGIN
>
>	DECLARE @Test int = 0
>
>	if @lcStr = '' or @lcList=''
>		set @test=1 
>	else 
>	if NOT (@lcStr is null or @lcList is null)
>	begin 
>		declare @aa int 
>		set @aa = charindex(','+@lcStr+',',','+@lcList+',')
>		if @aa>0
>			set @Test = 1
>		else 
>			set @test = 0
>	end 
>
>	RETURN @Test
>
>END
>GO
>

>
>then, in the conditional clause I would
>
>

>WHERE dbo.isIN([awb_manifestnumber], @awb_manifestnumber)>0
>

This is very bad as you're not using index this way and making query slow by adding scalar UDF into WHERE. I advise you to never use such approach.