Cannot connect to vnc server

[Pete Holsberg]

I installed and configured a VNC server as per 
http://ubuntuforums.org/showthread.php?t=122402, but when it try 
vncviewer linux from a terminal, I get

VNC viewer version 3.3.7 - built Mar  8 2007 21:56:52
Copyright (C) 2002-2003 RealVNC Ltd.
Copyright (C) 1994-2000 AT&T Laboratories Cambridge.
See http://www.realvnc.com for information on VNC.
vncviewer: ConnectToTcpAddr: connect: Connection refused
Unable to connect to VNC server

what should I try next?

Thanks.