SQLServer 2005 - How to convert from int to binary

CREATE FUNCTION [dbo].[FU_CONVERT_INTtoBIN] (@pincoming_number int)
RETURNS varchar(200)
as
BEGIN
-- 08/31/09 Converts from integer to binary JairoH

DECLARE @vbin_number VARCHAR(200)
SET @vbin_number = ''

IF @pincoming_number <> 0
BEGIN
WHILE @pincoming_number <> 0
BEGIN
SET @vbin_number = SUBSTRING('0123456789', (@pincoming_number % 2) + 1, 1) + @vbin_number
SET @pincoming_number = @pincoming_number / 2
END
END
ELSE
BEGIN
SET @vbin_number = 0
END

RETURN @vbin_number

END