new to Codeigniter

[eluser]Unknown[/eluser]
http://net.tutsplus.com/tutorials/php/co...r-library/

see source code on this page it is showing following error...plz help me
Not Found

The requested URL /calendar/mycal/ was not found on this server.
Apache/2.2.14 (Ubuntu) Server at localhost Port 80

[eluser]chandrajatnika[/eluser]
maybe you haven't setup the mod_rewrite and .htaccess

http://ellislab.com/codeigniter/user-gui.../urls.html