Problem: PHP installation does not support PostgreSQL

[Yang Mei Lin <meilin@bytecraft.com.my>]

I have installed the packages as below by using apt-get install in
Debian "Sarge" Linux.
i   php4           4.1.2-6              
ii  postgresql     7.3.4-9 
iii postgresql-cli 7.3.4-9  

But when I tried to install php4-pgsql by using apt-get install
php4-pgsql, the error message says that
 
The following packages have unmet dependencies:
  php4-pgsql: Depends: libpgsql2 (>= 7.2) but it is not installable
E: Broken packages

So, I tried to install php4-pgsql_4.3.1-26998_i386.deb by converting
from .rpm package. But, the result's my PHP installation does not
support PostgreSQL, need to recompile PHP using the --with-pgsql
configure option. Can somebody gives me some ideas how to solve it?