sub query is extermely slow

[sam wun]

Hi list,

The following sql statement takes 3 mintues to complete the query. How 
can I improve its speed?
select DISTINCT i.basename from inventory i, transaction t, customer c 
where i.prodcode = t.prodcode and c.custcode = t.custcode and i.basename 
is not NULL and i.prodname is not NULL and ((date(t.date) >= 
"2004-01-01" and date(t.date) <= "2004-01-31") and i.basename IN (select 
DISTINCT ii.basename from inventory ii, transaction tt, customer cc 
where ii.prodcode = tt.prodcode and cc.custcode = tt.custcode and 
ii.basename is not NULL and ii.prodname is not NULL and(date(tt.date) >= 
"2005-01-01" and date(tt.date) <= "2005-01-31"))) order by i.basename

Thanks
Sam