6 x 6 magic squares
requires JavaScript (MSIE recommended)
A mouseclick on any number of the greenbordered square ("numberpool") moves this number into the first empty
field of the redbordered square ("magic area");
a click on any number of the magic area brings the number back to its original place in the pool.
Aim: 
A magic square of size 6 x 6 is to be constructed, (with additional properties: nine of the 2x2 subsquares have equal sums and the inner 4x4 subsquare is pandiagonal).   When "show" or "quick" is activated, a backtracking algorithm will continue the search for a solution; interruption can be caused
by clicking the option "mouse". When a solution is found, the algorithm will stop, and in that case, a search for a next solution may be continued with the corresponding button. The bluebordered square always contains the last found solution.
The delay (in milliseconds) regulates the frequency of image output, if "show" is activated.
