You need to login to the system to find the button. For most of forum topic created by hwang, The first message usually contain one java simulation. And you should be able to find "GET APPLET FILES" near the end of the first message.! For example: login to this forum and check out [url=http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=226] Traffic light system[/url]