First I would explain what I am trying to do.
I have two tables.
First table has A, B and C fields.
Second table has A, D fields.
Second table has data related to first table and also some more data that is not first table
that is second table has some additional accounts(A) than first table. D(date) field data has to fall in the range of B and C date fields.
When I join these two tables,

join a in table2 to all a in table1 as j1

I would get the data like this:

A D B C
1234 03012004 03012004 03032004
1234 03062004 03012004 03032004
4567 11122004 . .

now, what I need to do is take out the records that has data that does not fall in the B and C range.
So, I added where statement after my join
table file table2
print ...
...
where (D ge B) and (D le C)

This would give me
A D B C
1234 03012004 03012004 03032004

But what I really need is this

A D B C
1234 03012004 03012004 03032004
4567 11122004 . .
so, I need data that has missing values.
I did try using where b or c is missing criteria. no luck with that.

Any ideas?

Thanks.

Try this where

where ((D ge B) and (D le C)) or B is missing

I tried that way. Not sure why it is not recognizing the missing data as missing values. If I give the oppisite where b is-not missing I am getting data that do not have missing data. It is doing the right way when I am asking the opposite of missing but not for missing values.
This might sound stupid, but this works. what I did is:
I hold the data first with hold format focus after the join like this.

table file table2
print ....
...
on table hold as hold1 format focus
end
table file hold1
print ...
where (b eq 0) or
((d ge b) and (d le c))
end
this works