function renderer(placement) {
	return function(data){
		placement.html(data);
	}
}

function get_cal_date(){
	return {y: $('#current-year').val(),
			m: $('#current-month').val()
		   };
}

function next_month(){
	var ym = get_cal_date();
	var callback = renderer($('#cal-wrapper'));
	var year = parseInt(ym['y']);
	var month = parseInt(ym['m']);
	if (month == 12) {
		year++;
		month = 1;
	} else {
		month++;
	}
	get_cal(year, month, callback);
}

function prev_month(){
	var ym = get_cal_date();
	var callback = renderer($('#cal-wrapper'));
	var year = parseInt(ym['y']);
	var month = parseInt(ym['m']);
	if (month == 1) {
		year--;
		month = 12;
	} else {
		month--;
	}
	get_cal(year, month, callback);
}

function get_cal(year, month, callback) {
	cal = $.get(cal_url, {y: year, m: month}, callback)
}