function setupCalendar() {
	$("#cal_button_left").hover(
		function() {
			prevHover($(this));
		},
		function() {
			if(checkYear("back")) $(this).css("background-position", "0px -19px");
			else $(this).css("background-position", "top left");
		}
	).unbind("click").click(function() {
		changeYear("back");
		prevHover($(this));
	});
	
	$("#cal_button_right").hover(
		function() {
			nextHover($(this));		
		},
		function() {
			if(checkYear("forward")) $(this).css("background-position", "-14px -19px");
			else $(this).css("background-position", "top right");
		}
	).unbind("click").click(function() {
		changeYear("forward");
		nextHover($(this));
	});
	
	$("#cal_button_left").css("background-position", "0px -19px");
}

function prevHover(button) {
	if(checkYear("back")) button.css({"background-position":"bottom left", "cursor":"pointer"});	
	else button.css({"background-position":"top left", "cursor":"default"});
}

function nextHover(button) {
	if(checkYear("forward")) button.css({"background-position":"bottom right", "cursor":"pointer"});	
	else button.css({"background-position":"top right", "cursor":"default"});
}

function checkYear(dir) {
	var year = $("#cal_year h3");
	var currYear = year.html();
	if(currYear != "" && !isNaN(currYear) && Math.round(currYear) == currYear) {
		if(dir == "back" && currYear == minYear) return false;
		else if(dir == "forward" && currYear == maxYear) return false;
		else return true;
	} else return false;
}

function changeYear(dir) {
	if(checkYear(dir)) {
		var year = $("#cal_year h3");
		var currYear = parseInt(year.html());
		var prevYear;
		
		if(dir == "back") {
			prevYear = currYear;
			currYear = currYear - 1;
			year.html(currYear);
			$("#cal_year"+prevYear).hide();
			$("#cal_year"+currYear).show();
		} else if(dir == "forward") {
			prevYear = currYear;
			currYear = currYear + 1;
			year.html(currYear);
			$("#cal_year"+prevYear).hide();
			$("#cal_year"+currYear).show();
		}
	}
	
	checkButtons();
}

function checkButtons() {
	if(checkYear("back")) $("#cal_button_left").css("background-position", "0px -19px");
	if(checkYear("forward")) $("#cal_button_right").css("background-position", "-14px -19px");
}