made the enhancement here
http://weelookang.blogspot.sg/2013/01/ajc-lesson-with-2-charges-simulation.html
made the enhancement to the electric field lines as proportional to strength of Q2.
thanks to goh khoon song for the feedback and use in his lessons.
Q1 is limited to -1 or 1, hence-fore.

download: https://dl.dropbox.com/u/44365627/lookangEJSworkspace/export/ejs_twopointcharges18q2work.jar
original authors: Fu-Kwun Hwang and lookang and szeyee
enjoy!