This script is designed for use in Mac-Labs. It should be placed in the Startup Items folder. It replaces the "Netscape Preferences" file (which is located in the "Netscape ƒ" folder inside the "Preferences" folder) with a default version (located in a folder called "Default Files"). It also closes any open widows in the Finder, cleans up the Desktop, and empties the trash, readying the machine for the next user.
This script could not have been written without the help of several members of the Mac-Managers and Applescript-users lists. Thanks!