Flexible searching on tables

CREATE PROCEDURE get_rows

@date_received      datetime, -- always supplied
@area_code 			varchar(50) = NULL, -- can be empty
@source_of_budget 	varchar(20) = NULL -- can be empty

AS

--//
DECLARE @result TABLE
(
int_row_id 			integer,
area_code 			varchar(50),
date_received 		datetime,
budget_source 		varchar(20)
)

--//
--//
INSERT
	@result
	(
	int_row_id,
	area_code,
	date_received,
	budget_source
	)
--//
SELECT 
	int_row_id, -- identity column
	area_code,
	date_received,
        budget_source
FROM 
	dbo.source_table
WHERE 
	( CONVERT(CHAR(10),date_received,101) > CONVERT(CHAR(10),@date_received,101) )

--//
IF @area_code IS NOT NULL
BEGIN
	--//
	DELETE

	FROM 
		@result

	FROM
		@result	t1
		
		LEFT JOIN 
			(
			SELECT 
				int_row_id
			FROM 
				@result
			WHERE ( area_code = @area_code )
			) t2

		ON t1.int_row_id = t2.int_row_id

	WHERE
		t2.int_row_id IS NULL		
	--//
END

--//
IF @source_of_budget IS NOT NULL
BEGIN
	--//
	IF @source_of_budget = 'Asia'
	BEGIN
		--//

		DELETE

		FROM 
			@result
	
		FROM
			@result	t1
			
			LEFT JOIN 
				(
				SELECT 
					int_row_id
				FROM 
					@result
				WHERE ( budget_source IN ('Philippines','Korea','Japan' ) )
				) t2
	
			ON t1.int_row_id = t2.int_row_id
	
		WHERE
			t2.int_row_id IS NULL	

		--//
	END

	--//
	--//
	ELSE
	--//
	--//

	BEGIN
		--//

		DELETE

		FROM 
			@result
	
		FROM
			@result	t1
			
			LEFT JOIN 
				(
				SELECT 
					int_row_id
				FROM 
					@result
				WHERE ( budget_source = @source_of_budget )
				) t2
	
			ON t1.int_row_id = t2.int_row_id
	
		WHERE
			t2.int_row_id IS NULL	

		--//
	END

END

--//
--//
-- final select
--//
--//
SELECT
	* -- whatever you want
	--//
FROM	
	dbo.source_table source
	--//
	INNER JOIN (SELECT DISTINCT int_row_id FROM @result) result
		ON source.int_row_id = result.int_row_id
	--//
ORDER BY
	--//
	source.int_row_id


RETURN