Getting rid of index/directory pages?

This is a very dumb question, I really should know the answer, but I don't.

Currently, if you go to mysite.com/afolder/, you'll get a directory listing of the directories contained in it. How do I stop this from appearing?

 

Change the unix file permissions on the folder, filezilla offers this option and you can just uncheck the "read" permission for quests.

 

You can also turn off the "Indexes" option for the directory in the httpd.conf or .htaccess files.

 

Thanks for the responses guys, I went with Craig's suggestion, seemed the easiest and it works! Thanks!

 

echo "Options -Indexes" >>.htaccess

 

I put a blank index.php or index.html file in the directory.