var startYear = 2002;
var currentYear = 2002;
var endYear = getYear();
var yearLabel = 'y';
var navLabel = 'Year';

function getYear() {
	date = new Date;
	return date.getFullYear();
}

function nextYear() {
	if(currentYear == endYear) {return false;}
	hideYear(currentYear);
	showYear(currentYear+1);
	currentYear++
	if(currentYear == endYear) {
		hideNavigation('next');
	}
	showNavigation('prev');
}

function prevYear() {
	if(currentYear == startYear) {return false;}
	hideYear(currentYear);
	showYear(currentYear-1);
	currentYear --;
	if(currentYear == startYear) {
		hideNavigation('prev');
	}
	showNavigation('next');
}

function setYear(year) {
    if(currentYear == year) { return false; }
    hideYear(currentYear);
    showYear(year);
    currentYear = year;
}

function showYear(year) {
	yearDiv = document.getElementById(yearLabel+year);
	yearDiv.style.display = 'block';
    yearLink = document.getElementById('span'+year);
    yearLink.className = 'yearLabelON';
}

function hideYear(year) {
	yearDiv = document.getElementById(yearLabel+year);
	yearDiv.style.display = 'none';
    yearLink = document.getElementById('span'+year);
    yearLink.className = 'yearLabel';
}

function showNavigation(dir) {
	navDiv = document.getElementById(dir+navLabel);
	navDiv.style.display = 'block';
}

function hideNavigation(dir) {
	navDiv = document.getElementById(dir+navLabel);
	navDiv.style.display = 'none';
}