// JavaScript Document
var m_interval_id = 0;
var m_current_image_num = 0;
var m_image_location = "images/front_sideshow/";  //Please make sure it ends in a slash
var m_image_url_list= new Array ("a.jpg","b.jpg","c.jpg","d.jpg","e.jpg");
var slideshow_frequency = 2000;                 // Refresh every 2 seconds (2000 ms)

function DisplayNewImage( sImageID ) {

	// Pick a new image to display
	var prev_state = m_current_image_num;
	var curr_state = m_current_image_num + 1;
	if (curr_state >= m_image_url_list.length ) { curr_state = 0; }
	var next_state = curr_state + 1;
	if (next_state >= m_image_url_list.length ) { next_state = 0; }
	
    m_current_image_num = curr_state;
	var curr_image = m_image_location + m_image_url_list[curr_state];
	
	// Assign new image to image in container object
	var idImageID = document.getElementById( sImageID );
	if (idImageID && curr_image) {
		idImageID.src = curr_image;
	}

	var prev_image;
	var next_image;
	prev_image = m_image_location + 'thumbs/' + m_image_url_list[prev_state];
	curr_image = m_image_location + 'thumbs/' + m_image_url_list[curr_state];
	next_image = m_image_location + 'thumbs/' + m_image_url_list[next_state];

    idImageID = document.getElementById( sImageID + '_thumb_1' );
	if (idImageID && prev_image) {
		idImageID.src = prev_image;
	}
	idImageID = document.getElementById( sImageID + '_thumb_2' );
	if (idImageID && curr_image) {
		idImageID.src = curr_image;
	}
	idImageID = document.getElementById( sImageID + '_thumb_3' );
	if (idImageID && next_image) {
		idImageID.src = next_image;
	}

	return;
}

// Given:
//      "id" of image tag to update the slideshow
//		image location directory, makes sure it ends in a trailing slash
//      Frequency to update images
//      Usage: StartSlideshow( 'slidshow_img1', 'images/slideshow_images/', 5000 );
function StartSlideshow( sImageID, image_loc, iFreq ) {

	// Without an image ID tag to update, nothing to do
	if (!sImageID) {
		return;
	}

	// Overide default image location, if provided
	if (image_loc) {
		m_image_location = image_loc;
	}
	
	// Change frequency if provided, othewise it will use the default	
	if (iFreq) {
		m_slideshow_frequency = iFreq;
	}

	// Start up interval update
	m_interval_id = setInterval( 'DisplayNewImage(\'' + sImageID + '\');' , m_slideshow_frequency );
	
	return;
}