changes made

1 redesign layout and color scheme
2 add v and lambda slider controls
3 add time to show the progress for student to use v to calculate how much the wave move
4 add the 4 types of visualization
5 add the 10 mode of color visualization
6 add legend, suspect buggy but will try to activate it for relation learning to the visualization meaning of color
7 add S1 and S2 y displacement as vertical bar for understanding of phase difference at the sources S1 and S2
8 add y1 and y2 and y1+y2 for the y displacement for understanding of superposition of point P
17Jan2010
9 added coherence and incoherence check-box for exploring what if scenario for exploring in-depth the meaning of incoherence.
incoherence here refer to v=!v2 || f=!f2 || lambda=!lambda2
31January 2011
10 added screen effects (instantaneous patterns and average intensity patterns)  of the interference patterns for both coherent and incoherent sources from http://www.cabrillo.edu/~jmccullough/Applets/OSP/Oscillations_and_Waves/waves_interference.jar by  Juan M. Aguirregabiria. now it is very easy to visualize the meaning of coherent sources. :)
10 February 2011
11 add check box to visual true S1, S2 and P bar values
12 add check box for visual instant and average pattern of the end of the screen for relating to future cases of interference as such light waves
13 made S1 and S2 show when radio buttons are selected
14 fix a bug on the S1 and S2 bar with phase is change
15 made the area to display top view of ripple tank bigger to solve the bug of a line showing
16 made some animated gif to others to use here http://weelookang.blogspot.com/2011/01/ejs-open-source-ripple-tank.html
13 February 2011 Sunday
made the screen on the right more obvious by adding BR text "screen on the right"
made all number 0.00 for consistent reading
add hint for activating the side views
30 March 2011
fix bug
the border on top and right corner of ripple tank is due to a fix relationship for the screen effect arrayoutofbound error that i cannot seem to fix
arrange the code inside
04 Jan 2012
reintroduce a side view versus time of the displacement at point P. the displacement-time graphs of S1, S2 and the resultant at any position P
fixed some 0.00 format on the bars of S1 S2 and P
fixed the bug by moving the codes to evolution page instead of fixed relationship, was difficult to find the bug or cause, but i did it!
made hide and show after clicking the check-boxes, a bit neater now, we agree that it could be still useful to be able to fine-control position of S1 and S2, let keep it inside the sim
dded a margin 10%, now can see the maximum and minimum values of 2 and -2 easily.
05 Jan 2012
selectable width now using split panels