I hope the following simulation is what you need!

***Click [eye]

translate strings in simulation to different language format before download
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(1093.4kB):double click downloaded file to run it. (4 times by 3 users) , Download EJS source View EJS source
[/eye] to view simulation. ***