Calling a table residing in another database from Plpgsql

Hi,

I have function called test1() in database 1. I need to input the value
from this function into another table which is in database2.

How can i achieve this task in plpgsql. I went through some documentation
and found out that it is possible through dblink.

I infact downloaded the dblink package in contrib folder. But still when i
tried to use dblink in the following manner:

SELECT * from dblink('host=192.168.0.50 dbname=AK1 user=akteam','Select
userid from user_reg') as t (userid integer);

I am getting an error as "ERROR: function dblink("unknown", "unknown")
does not exist"

Is dblink the only way of connecting the databases and if so what is the
exact step by step procedure to be follwed to download dblink and use it
to connect databases.

Thanks in advance,
Regards,
deepthi