How To Return A Static Value?

I have the following stored procedure...

CREATE Procedure UserGetInfo2
 (
@UserID int, @SystemTimePeriodID int
 )
As
 set nocount on
SELECT     Users.UserId as UserID, Users.UserName as UserName, Users.RealName as RealName, UserTimePeriod.BudgetCode as BudgetCode, UserTimePeriod.SystemTimePeriodID as SystemTimePeriodID, Users.Password as Password, Users.SSN as SSN, Users.Location as Location, Users.ScheduleType as ScheduleType, Users.EmployeeType as EmployeeType, Users.TimeAccounted as TimeAccounted
FROM      Users INNER JOIN UserTimePeriod ON Users.UserId = UserTimePeriod.UserID
WHERE     (users.userID= @UserID) AND (UserTimePeriod.SystemTimePeriodID = @SystemTimePeriodID)
return
GO


The problem lies in that when a person has a SystemTimePeriodID over a certain value, there is no UserTimePeriod record since it has not been created yet.

Obviously, I need to wrap this in an IF...EXISTS


IF EXISTS (SELECT UserTimePeriodID FROM UserTimePeriod WHERE (SystemTimePeriodID = @SystemTimePeriodID) AND (UserID = @UserID)) 

(the SELECT above, since that's what needs to come back if the data exists) 

ELSE

Do the same select but put in a static value for BudgetCode, like '0000' 

GO

How could I do the part where the IF...EXISTS fails?

I'm... not sure I can use RETURNS, since it feeds into this recordset:

rstUserInfo2.Open "UserGetInfo2 " & Request("UserID") & ", " & Request("SYSTIMEPERIODID") 

and later uses values from that RecordSet, such as <td><%=rstUserInfo("BudgetCode") & ""%></td>