Multiple sub SQL not working

Hello,

I am able to run the 1st pass through SQL

select count(*) as cnt1,

         (select count(*) as cnt2 from table1 where var1 is null)

from table1

However, the 2nd SQL failed with "undefined index" error message.

select count(*) as cnt1,

         (select count(*) as cnt2 from table1 where var1 is null),

         (select count(*) as cnt3 from table1 where var1<0)

from table1

Does anybody know why?

Thanks.