configuring for winnt proxy

hi,
Anyone plz help.I have redhat 6.1 internet client of winnt proxy using dailup connection.M/c is dailing and logging to winnt server porperly.Proxy requires authentication for each browser.After that if u open browser it does not show any site.It ping properly to proxy server.Same setting is working properly in win98 on same m/c.It is using port 80.If put ip address
of proxy server it is connecting there and asking for authentication.But for other sites it is not working.I think problemis that name to ip address resolution is not happenning.
Any one who knows about configuring linux as proxy client plz give details of configuration.
thanks.