Create Login Script (using email address)

I have some code that was given to me to create user logins based on email addresses.  I'm having issues getting it to run more than once and create a multiple logins (using different login types).  I'm thinking this code just isn't going to work for me, especially as I will need to run it as a nightly job to create logins automatically for new accounts that are created.  Does anyone have any code or a report/utility they are willing to share that will create web logins from using email addresses or can anyone take a look at the code I have and give me some advice on how to edit to make it work?

Thanks everyone!!!!

Teresa

USE [impresario]
GO
/****** Object:  StoredProcedure [dbo].[LP_CREATE_LOGINS_FROM_EADDRESS]    Script Date: 02/22/2011 13:52:42 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

-- =============================================
-- Description:    Stored procedure to search for primary email addresses that do
-- not have a corresponding entry in T_CUST_LOGIN and create one.
-- Optional parameter of start_dt (being the create_dt to look for on existing
-- primary records in t_eaddress which don't have a corresponding record in t_cust_login,
-- then creates a login for them).
-- =============================================
ALTER PROCEDURE [dbo].[LP_CREATE_LOGINS_FROM_EADDRESS] @start_dt datetime = null
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

if @start_dt is null
 begin 
 truncate table lt_login_info
   insert lt_login_info (customer_no, n1n2_ind, login_type, login, password, eaddress_no,
  primary_ind, inactive)
 select customer_no,'3','2',address,customer_no,eaddress_no,'N','N'
  from t_eaddress 
  where primary_ind = 'Y'
  and create_dt between getdate()-1 and getdate()
    and eaddress_no not in (select eaddress_no from t_cust_login)
    and customer_no > 0
      and address like '%@%'
end
 else 
 truncate table lt_login_info
   insert lt_login_info (customer_no, n1n2_ind, login_type, login, password, eaddress_no,
  primary_ind, inactive)
 select customer_no,'3','2',address,customer_no,eaddress_no,'N','N'
  from t_eaddress 
  where primary_ind = 'Y'
   and create_dt between @start_dt and getdate()
    and eaddress_no not in (select eaddress_no from t_cust_login)
    and customer_no > 0
      and address like '%@%' 

select * from lt_login_info

insert t_cust_login
 (login_no, customer_no, n1n2_ind, login_type, login, password, eaddress_no,
  primary_ind, inactive)
select a.customer_no + (select max(login_no) from t_cust_login), a.customer_no,
  a.n1n2_ind,a.login_type,a.login,a.password,a.eaddress_no,a.primary_ind,a.inactive
  from lt_login_info a
   
update t_next_id
set next_id = (select max(login_no) from t_cust_login) + 10
 where type = 'LO'

END

/*
create table lt_login_info
    (customer_no int,
    n1n2_ind int,
    login_type int,
    login varchar(80),
    password varchar(32),
    eaddress_no int,
    primary_ind char(1),
    inactive char(1))
*/

/*
EXEC LP_CREATE_LOGINS_FROM_EADDRESS '2000-01-01'

select * from t_cust_login
select * from tr_login_type
select * from t_next_id where type = 'LO'

select login, count(login) from t_cust_login
group by login
having count(login) >1

update t_cust_login
set temporary_ind = 'Y'
where create_dt > '2011-01-03'

delete from t_cust_login
where customer_no in
    (select customer_no
    from t_customer
    where inactive in (2,5))
*/