You have to use the option Indexes in the Apache configuration.
For instance, in the .htaccess file for your directory (if you can use those, and have sufficient privilegies), you could put :
Options +Indexes
This functionnality is provided by mod_autoindex
, which has lots of options to allow fine-tunning of the generated output, btw
To get this working, that module must be loaded, and to be able to activate the option in an .htaccess file, you will need the admin of the server to give you some privilegies (with the AllowOverride
directive in the Apache's main config file, if I remember correctly -- well, your admin should know that better than me anyway ^^ )