if the name in applet tag is ejscode (name='ejscode')
And there is a variable call dt in ejs model.
You can get dt value with the following call:
Please check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=714.0]Quiz: Do you know when two particles have the same horizontal speed?[/url]
It was only work for Internet Explorer and it is not working for netscape at that time.
However, the code has been disabled in the current version.
It is at the end of org/colos/ejs/library/simulation.java
You can try to enable the code and re-compile it again if you really need it.