Using variables in Stored Procedure

SET QUOTED_IDENTIFIER ON 
GO
SET ANSI_NULLS ON 
GO


ALTER   procedure GetRecruiterApplicants
	@userid	varchar(50),
	@trackerGroup varchar(50),
	@sortBy varchar(20),
	@dir varchar(5)

as
begin

set nocount on

SELECT C.USERID INTO #VU FROM VUSERS V WITH (NOLOCK), COMPANIES C WITH (NOLOCK) 
WHERE CHARINDEX(','+C.USERID+',', ','+VUSERS+',')>0 AND V.USERID=@userid
UNION SELECT @userid

SELECT distinct l.AccessCode, l.ApplicantGivenName, l.ApplicantFamilyName, l.DateCreated, l.DateApplicantAccessed, p.ApplicationTitle, l.disabled
FROM chamslinks l, chamsProjectIDs p, chamsGroups g 
WHERE l.TrackerID IN (SELECT userid FROM #VU) 
	AND g.trackerGroup = @trackerGroup 
	AND p.groupTblID = g.groupTblID 
	AND p.ProjectID = l.ProjectID
ORDER BY l.@sortBy @dir

DROP Table #VU

set nocount off
end