Can't connect to the postgresql server

Dear all,

I just installed postgresql 0.8.3 on the fedora core linux 3, I also
installed pgadmin 1.0.2 in my computer. But I am having trouble connecting
postgresql by using pgadmin, it shows me the error message" An error
occurred: Error connecting to the server: could connect to server:
Connection refused (0x0000274D/10061) Is the server running on host
"192.168.3.118" and accepting TCP/IP connections on port 5432?"

I am pretty sure that the postgresql server is running, but I figured it's
because the command I use to run the postgresql serve is not quite right and
the port 5432 is not open to listen to the request since I didn't find port
5432 after using namp to check the open port on the linux server.

Anybody has idea how to solve this problem?

Thanks in advance.

Chris