temporary table stored procedure help please

hi i have the following, but i want to define @r1 and @r2 etc as querystrings.. how do i do this?:
DECLARE @diff TABLE (
ID bigint,
r1d smallint, r2d smallint, dif int )

INSERT INTO @diff (ID, r1d, r2d)
SELECT     ID, r1, r2
FROM     dbo.type


UPDATE     @diff
SET     r1d = r1d-@r1 //(r1 is querystring and how make result show as positive number?)
    r2d = r2d-@r2
    dif = r1d+r2d



SELECT TOP(1) ID
FROM @diff
ORDER BY dif ASC
...