var currentScreenshot = 1;
var screenshotCount = 9;
function showScreenshot (screenshotNumber) {
	$('screenshot' + currentScreenshot).addClassName('hidden');
	$('screenshot' + screenshotNumber).removeClassName('hidden');
	
	$('thumbnail' + currentScreenshot).removeClassName('selected');
	$('thumbnail' + screenshotNumber).addClassName('selected');
	
	currentScreenshot = screenshotNumber;
	return false;
}
function nextScreenshot () {
	var screenshotNumber = currentScreenshot + 1;
	if (screenshotNumber >= screenshotCount) {
		screenshotNumber = 0;
	}
	showScreenshot(screenshotNumber);
}
function previousScreenshot () {
	var screenshotNumber = currentScreenshot - 1;
	if (screenshotNumber == -1) {
		screenshotNumber = screenshotCount - 1;
	}
	showScreenshot(screenshotNumber);
}