how to set the base_url

[eluser]ganesh_tavva[/eluser]
iam using Apache/1.3.33 Server at www.webladdu.com Port 80
i place the files to filezila web server
i modified config and database file according to our need
it displays 404 page not found
base_url=www.webladdu.com/ezauth/" it is not working how to modify the .htaccess file.i did n't any changes in .htaccess file

thanks