var calendar;
var btn;

var testVisibility = function() {
	calendar = $('FSdateSelector');
	if (calendar && calendar.getStyle('visibility') == 'hidden') {
		calendar.hide();
	} else if (calendar) {
		calendar.show();
	}
}

Event.observe(window, 'load', function() {
	var pe = new PeriodicalExecuter(testVisibility, .5);
});