In order to use posgressql6.5.1,i designed a simple function like  this:
function sim()
{$conn=pg_connect($connoptions);
 $result=pg_result($conn,"....");
 ....
 pg_freeresult($result);
 pg_close($conn);}

when i use a for() circle to use the function, there's problem.
each first time use the funtion, it's ok, but the sencond time, it goes wronglike this:
Warning: 1 is not a valid PostgreSQL link resource in .... on line ...
and the third time ,It runs well.and the fourth time, mistakes happened again. and so on.
I've track the $conn, the resource id  are:#1,#1,#7....

When i turned to mysql, thereis no problem.

Sorry for my poor english.
Regards