I downloaded the source and ran this command ./configure in terminal
pg_config was not located after reading "readme" file i modified the command by adding PG_CONFIG=..../postgresql-8.2.3/src/bin/pc_config every thing was ok but in the end i got this configure error:
configure: error:
Can't findl libpq-fe.h in . Are you sure the libpq
headers are installed correctly? They should be in the directory returned by
"pg_config --includedir".

If you do have libpq (the C-language client library for PostgreSQL) installed,
make sure you have the related development materials--mainly its header files--
as well as the library binary. Some system distributlions keep the two in
seperate packages with names like "alibrary" and "alibrary-dev", respectively.
In that case, make sure you have the latter installed as well.
libpq-fe.h is located in

it says the file can't be located however its in the mentioned directory

please help