Persistence of Stack Frames

We escalate further:

var u = function (){var cnt = 0; var cntPair = new Object();
  cntPair.inc = function (){++cnt;};
  cntPair.read = function (){return cnt;};
  return cntPair;};
var p1 = u();
var p2 = u();
p1.inc(); p1.inc(); p2.inc();
document.write("p1's count is " + p1.read());
document.write("<br>p2's count is " + p2.read());

p1's count is 2
p2's count is 1

Bravo! It seems that not only the value of cnt is retained, but its mutable storage as well!