createdb: could not connect to database

Dear All

I have just installed postgres 8.1.2 on a computer running Fedora Core
4 with the rpms got from postgres site. However, I get the following:


$ createdb mydb
createdb: could not connect to database postgres: could not connect to
server: No such file or directory
        Is the server running locally and accepting
        connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
$

Any idea about how to overcome the problem?

Thanks in advance,

Paul