Our program using EJS is used differently that you would not use java codes or the java applet coz we only know HTML and QBASIC. It isn't draggable. In order to operate our program, the user will just use EJS and in the model, he/she may enter different values for the 3 different variables (f for focal length, d for distance of the object from the mirror and h for the height of the object). That is all what we can do.
We'll do our best to improve our program!
Thanks for everything! ;D