var arr_rot_list = new Array();

var current_index = 0;
var prev_index = -1;

var ROTATE_DELAY_TIME = 3000;
var FADE_DELAY_TIME = 60;
var FADE_SPEED = 3;

var opacity = 100;

var fade_time_id = null;

var current_size = 0;

function rotate_images()
{
	current_size = arr_rot_list.length;
	for (var idx = 0; idx < current_size; idx++)
	{
		var rotation = document.getElementById(arr_rot_list[idx][0]);
		if (!rotation)
		{
			continue;
		}
		var image_list = rotation.getElementsByTagName("IMG");
		
		arr_rot_list[idx][2] = arr_rot_list[idx][1];
		arr_rot_list[idx][1] = (arr_rot_list[idx][1] + 1) % image_list.length;

		var prev_image = image_list[arr_rot_list[idx][2]];
		var current_image = image_list[arr_rot_list[idx][1]];

		current_image.style.display = '';
	}
	
	opacity = 100;

	fade_time_id = window.setInterval
	(
		function()
		{
			fade_image()
		},
		FADE_DELAY_TIME
	);
}

function fade_image()
{
	for (var idx = 0; idx < current_size; idx++)
	{
		var rotation = document.getElementById(arr_rot_list[idx][0]);
		if (!rotation)
		{
			continue;
		}

		var image_list = rotation.getElementsByTagName("IMG");
		
		var prev_image = image_list[arr_rot_list[idx][2]];
		var current_image = image_list[arr_rot_list[idx][1]];

		prev_image.style.opacity = opacity / 100;
		prev_image.style.filter = 'alpha(opacity=' + (opacity) + ')';

		current_image.style.opacity = (100 - opacity) / 100;
		current_image.style.filter = 'alpha(opacity=' + (100 - opacity) + ')';

		opacity -= FADE_SPEED;
	}

	if (opacity < 0)
	{
		prev_image.style.display = 'none';
		window.setTimeout("rotate_images()", ROTATE_DELAY_TIME);
		window.clearTimeout(fade_time_id);
	}
}

function setup_rotation(param_rot_id)
{
	
	var rotation = document.getElementById(param_rot_id);

	if (!rotation)
	{
		return;
	}
	var image_list = rotation.getElementsByTagName("IMG");

	if (image_list.length > 1)
	{
		var len = arr_rot_list.length;
		
		arr_rot_list[len] = new Array();
		
		arr_rot_list[len][0] = param_rot_id;
		arr_rot_list[len][1] = 0; // index 0: id, 1=> current, 2=> prev
		
		if (len == 0)
		{
			window.setTimeout("rotate_images()", ROTATE_DELAY_TIME);
		}
	}
}