Easy question

Hi I have no clue on PHP.

This is my code

<?php
$config["rootDir"] = "media/"; // Directory to start in.
$config["hideDir"] = ".,..,ievinc"; // List of directory names to be hidden from the system, system folders, etc. Use a , to seperate folders. NOT CASE SENSATIVE! (All folders that start with _ are hidden by default.)
$config["showExt"] = ".mp4,.mp3,.m4a,.mov,.m4v"; // Extensions of files that should be shown by system.
$config["template"] = "default"; // Template to use.
?>

I don’t just want it to display those file types. so if I delete the line, none of the files are displayed. How do I get it to display all extensions without typing them all in.