preventing directory listings

[Denver J. Saldanha]

Hi,
 
I am using tomcat 3.3.1a. Now when i type sin the url http://localhost:8080/
<http://localhost:8080/>  I can see the directory listing. Is there any way
to prevent this. Could you please let me know about this if there is a way. 
 
Thanks and Regards
Denver Saldanha