IF @source = @target 
	RETURN 
ELSE 
BEGIN
	IF @source < @target
		SET              @step = 1 
	ELSE
		SET              @step = - 1


		SELECT     @s_id = id
                           FROM         howtos
                           WHERE     pos = @source

	WHILE @source <> @target  
	BEGIN
		SET	@t_pos = @source + @step 
		SET	@s_pos = @source

		SELECT     @t_id = id
             		FROM         howtos
             		WHERE     pos = @t_pos
                                                                                  
		UPDATE    howtos
		SET              pos = @s_pos
		WHERE     id = @t_id

		UPDATE    howtos
		SET              pos = @t_pos
		WHERE     id = @s_id

		SET @source = @t_pos

	END
END