Infinity

Just enjoy this construction...

 var board = JXG.JSXGraph.initBoard('jxgbox', {originX: 300, originY: 300, unitX: 50, unitY: 50})
 var S = board.createElement('slider', [[-5,-6],[5,-6],[0,0.5,1]], {name:'S'});
 var points = new Array();
 points[0] = board.createElement('point',[5, 5], {name:' '});	
 points[1] = board.createElement('point',[-5, 5], {name:' '});	
 points[2] = board.createElement('point',[-5, -5], {name:' '});	
 points[3] = board.createElement('point',[5, -5], {name:' '});	
	 		 	
 function quadrangle(pt, n) {
  var arr = new Array();
  for(var i = 0; i < 4; i++) {
   arr[i] = board.createElement('point', 
         [function(t) {
            return function () {var x = pt[t].X(); 
                                var x1 = pt[(t+1)%4].X(); 
                                var s = S.X();
                                return x+(x1-x)*s;
                         }}(i), 
          function(t) {
            return function () {var y = pt[t].Y(); 
                                var y1 = pt[(t+1)%4].Y(); 
                                var s = S.X();
                                return y+(y1-y)*s;
                         }}(i)
          ], 
          {style:3, name:" "});
  }
  board.createElement('polygon',pt, {fillColor: '#5555'+n+''+n});
  if(n>0)
    quadrangle(arr, --n);
 }
 board.suspendUpdate();
 quadrangle(points,30);
 board.unsuspendUpdate();