Please check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=34.0]EJS tutorial (How to create simulation with EJS)[/url] to find other tutorials.
There are many swf tutorials in Chinese can be found at http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=656.0
It is fine if you do not understand Chinese characters, but you can get the ideals how it works.
If you are really interested in EJS, try to use it. And you are welcomed to post any questions related to it.
Post what you want to do and attach the xml file. And I will try to help you solve it (create the simulation you want).