function special_poll(max_choices) {
	this.count = 0;
	this.max_choices = max_choices;
	
	this.increment = function (cb) {
		if(cb.checked) {
			this.count++;
		} else {
			this.count--;
		}
		
		if(this.count > this.max_choices) {
			alert("Sorry, you may only select "+this.max_choices);
			cb.checked = false;
			this.count--;
		}
	}
}