>I could not get it to work. But thanks for the message.

Try this instead

CREATE CURSOR Tbl1 (fldID int, fld2 C(10))
INSERT INTO tbl1 VALUES (1,'')

INSERT INTO tbl1 values (2, 'B') 
INSERT INTO tbl1 VALUES (3, 'C') 

CREATE CURSOR Tbl2 (fldID int, fld2 C(10))
INSERT INTO tbl2 SELECT 1,'' FROM tbl1 ;
union SELECT 2, 'BB' FROM tbl1 ;
union SELECT 3, '' FROM tbl1 ;
union SELECT 4,'DD' FROM tbl1


select FldID, Fld2 from Tbl2 where exists ;
 (select 1 from Tbl1 where Fld2 = space(10) and FldID = Tbl2.FldID) OR Fld2<>SPACE(10) ;
UNION ;
select FldID, Fld2 from Tbl1 where exists (select 1 from Tbl2 where Fld2 = space(10) and FldID = Tbl1.FldID)

Sorry for taking so long, worked on the other thing in the moment.