window.addEvent('domready', function() {

	if($('prev_link') && $('next_link')) {
		
		var calendarAjax = new Request.HTML({
			url: '/includes/box-calendar-ajax.php',
			method: 'post',
			update: 'calendar_box',
			onComplete: function(e) {
				addEvents();
			}
		});
				
		function addEvents() {
				
			$('prev_link').addEvent('click', function(e) {
				e.stop();
				previousMonth()
			});
			$('next_link').addEvent('click', function(e) {
				e.stop();
				nextMonth();
			});
		}
		
		function nextMonth() {
			calendarAjax.get({year_param: $('next_year_param').value, move_param: 'next'});		
		};
		
		function previousMonth() {
			calendarAjax.get({year_param: $('prev_year_param').value, move_param: 'prev'});
		};

		addEvents();
	}
});