SQL Help

Hello!

I have a tabe :
addates :  (adid int 4,rundate date,posted boolean,dateid  int4 unique
create no. from sequence datesequence)

table is like this
                                    adid
rundate                   posted        dateid
                                    1031       05-17-1998
t                 1856
                                    1031       06-20-1998
t                 2032
                                    1031       06-23-1998
t                 2056
                                    1031       06-30-1998
f                 2077
                                    1055       05-21-1986
t                  456
                                    1055       01-01-1998
t                  987
                                    1055       06-30-1998
f                  2089
       I do have lots of entries like this - 30,000 rows

what I want to find is -adid of  records that has posted=f  for one
pertticuler day (ex. 06-30-1998)  and last run date (maximum date value
which is mark as true for each and every record of adid field)

should be like this          adid      rundate              lastposted
date      datedid
                                    1031     06-30-1998
06-23-1998         2077
                                    1055     06-30-1998
01-01-1998         987
How do I do this??

Thank you very much in advance for any thoughts.

Cheers

Anil