Using Variables In Stored Procedure

I am writing a stored procedure that basically gets a whole lot of info. Simple enough... that part works. Now I want to add functionality to pass in sortBy and direction variables so the results can be sorted from a web page. The code I have is:


Code:


SET QUOTED_IDENTIFIER ON
GO
SET ANSI_NULLS ON
GO


ALTER procedure GetRecruiterApplicants
@useridvarchar(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



The error I am getting is: "Server: Msg 170, Level 15, State 1, Procedure GetRecruiterApplicants, Line 24
Line 24: Incorrect syntax near '@dir'."

Any help?