create procedure modul_11 (@@number varchar(15))
as
begin
	/*
	**procedure to calculate modulus-11 checkdigit
	**procedure written 19980828 by andreas birgerson
	**last revision on  19981103 by andreas birgerson
	*/
	set nocount on
	
	declare @@max smallint
	declare @@counter smallint
	declare @@weight varchar(24)
	declare @@rest smallint
	
	select @@weight='864235978642359786423597'
	select @@max=datalength(@@number)
	select @@weight=right(@@weight,@@max)
	
	if  not @@max between 4 and 20 begin
	raiserror('Modul-11 invalid argument length',2,-1) with seterror
	return
	end
	
	create table #f (chkdigit smallint)
	select @@counter=@@max+1
	
	loop:
	select @@counter=@@counter-1
	insert #f select
	(ascii(substring(@@weight,@@counter,1))-48)*
	(ascii(substring(@@number,@@counter,1))-48)
	
	
	if @@counter >1 goto loop
	
	
	select @@rest=sum(chkdigit)%11 from #f
	
	select "Checkdigit"=
	case @@rest
	when 0 then 5
	when 1 then 0
	else 11-@@rest
	end
	
	drop table #f
	set nocount off
end
GO

GRANT EXECUTE ON MODUL_11 TO PUBLIC
GO