var vertical = 0;
var horizontal = 1;

var default_src = null;

var imgs = new Array();

imgs[vertical] = new Image();
imgs[vertical].src = 'images/ft_ver.gif';

imgs[horizontal] = new Image();
imgs[horizontal].src = 'images/ft_hor.gif';

function fold(direction, destination)
{
        play_paper();
        fold_helper(2, direction, destination);
}

function fold_helper(times, direction, destination)
{
	if(times <= 0) {
		document.location = destination;
		setTimeout("display_default()", 500);
		return;
	}

	// change image to next direction
	display_direction(direction);
	direction = (direction + 1) % 2;
	times--;
	setTimeout("fold_helper(" + times + "," + direction + ", '"
                        + destination + "')", 500);
}

function play_paper()
{
	var paper_sound = document.getElementById('papersound');

	if(paper_sound.Play != null)
		paper_sound.Play();
}

function display_direction(direction)
{
        display_image(imgs[direction]);
}

var did_alert = false;
function display_default()
{
	if(default_src == null && !did_alert) {
		did_alert = true;
		alert('Error displaying default image.');
	}
	document.getElementById('menu').src = default_src;
}

function display_image(image)
{
        if(default_src == null) {
                default_src = document.getElementById('menu').src;
        }
	document.getElementById('menu').src = image.src;
}