With the view parameters set as follows:

vp_Active = .T.
vp_idnum = '*'
vp_last = 'A%'
vp_first = '*'
vp_middle = '*'

shouldn't the following view definition return only records that have
lastname beginning with 'A' and empty(disdate)?   It doesn't - it returns
records that have lastname beginning with 'A' regardless of disdate.
Am I missing something simple?

SELECT Clients.cidnum, Clients.clastname, Clients.cfirstname,;
  Clients.cmiddlename, Clients.cadmdate, Clients.disdate;
FROM cms!clients;
WHERE Clients.cidnum LIKE ?vp_idnum;
   OR (UPPER(Clients.clastname) LIKE UPPER(?vp_last));
   OR (UPPER(Clients.cfirstname) LIKE UPPER(?vp_first));
   OR (UPPER(Clients.cmiddlename) LIKE UPPER(?vp_middle);
   AND EMPTY(Clients.disdate) = ?vp_active)