ALTER PROCEDURE [dbo].[rep_seminars]

   @from_date datetime
 ,@to_date datetime
,@Country_id int
AS
BEGIN
	
	SET NOCOUNT ON;


if @country_id=0
set @country_id=null


SELECT     Seminars.Venue_id, Venues.Venue_Name, Venues.Country_id, 
Countries.Country,
 CONVERT(datetime, Seminars.Start_Date, 103) AS start_date, 
                    dbo.Users_sys.Given_Names + '  '
 + dbo.Users_sys.SurName AS Presenter
FROM         Seminars LEFT OUTER JOIN
                      Venues ON Seminars.Venue_id = Venues.Venue_id LEFT OUTER JOIN
                      Users_sys ON Seminars.Presenter_id = Users_sys.user_id LEFT OUTER JOIN
                      Countries ON Venues.Country_id = Countries.Country_id
WHERE 
    
  ((Seminars.Start_Date BETWEEN  @from_date  AND @to_date) 
AND (Countries.Country_id = @Country_id or @Country_id is null ))

or

((@from_date is null and @to_date is null) and
(Seminars.Start_Date >= CONVERT(smalldatetime, getdate(), 103))
AND 
(Countries.Country_id = @Country_id or @Country_id is null))

END