I do not know why you registered with several accounts(with different user name, for examples: the above two mesaages are posted by you and you also post some other message with different username). Are you realy a teacher? Could you tell me why you post the following [url=http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=65]message[/url] with another username on our forum: [quote:296bbea393]Physics=Boring!!!!![/quote:296bbea393] *** The above two messages and the quoted one are posted from the same IP within 10 minutes *** If you are really a teacher: I am sorry that you find our applets are useless for you students. I am also sorry that you feel physics is boring. I do enjoy the fun of physics very much! I am willing to help you if you could tell me what kind of applet (in detail) you really want. I did what I could to help and many teachers do find our applets helpful for their teaching. That is why there are so many mirror sites around the world. If I find something is not good enough , I would not just complained about the situation. I will really do something to help (our children). I will try to help you if you could tell me the design of an applet you think it will be good for helping student to understand the physics concept. :roll: