Monty Hall resolution by Javascript

monthy-hall.js

var g = { change:0, dontchange:0  };
var p = 3;
var i = 1;
rnd = function(max) { return Math.floor(Math.random()*max); }
setInterval(function(){
	var doors = [];
	for (var j=0; j<p; j++) doors.push(0);	
	doors[rnd(p)] = 1; 
	var my_ch = rnd(p);
	var pr_chs = [];
	for (var j=0; j<p; j++) {
		if (j==my_ch) continue;
		if (doors[j]==0) pr_chs.push(j);
	}
	var pr_ch = pr_chs[rnd(pr_chs.length)];
	var ports_av = [];
	for (var j=0; j<p; j++) {
		if (j==my_ch) continue;
		if (j==pr_ch) continue;
		ports_av.push(j);
	}
	my_new_ch = ports_av[rnd(ports_av.length)];	
	g.dontchange += doors[my_ch];
	g.change += doors[my_new_ch];
	g.dontchangep = g.dontchange/i;
	g.changep = g.change/i;
	i++;
}, 0);