Pankaj Kumar wrote:
> below are client as well as server code...(i've simply copied the 
> programs from the web 
> site"http://www.tldp.org/HOWTO/XML-RPC-HOWTO/xmlrpc-howto-ruby.html").

This howto seems to contain a spelling mistake, that you copied as well:

> ************************************
> #server side prog(ruby_s.rb)
> 
> require "xmlrpc/server"
> 
> s = XMLRPC::CGIServer.new
> 
> s.add_hanlder("sample.sumAndDifference") do |a,b|
s.add_handler(...
>   { "sum" => a + b, "difference" => a - b }
> end
> 
> s.serve

You should try to find the place where your http server writes its 
logfile to and observe it, in order to find out what the exact cause of 
server errors is.

-- 
Florian Frank