box_open_class = 'box_open';
box_closed_class = 'box_closed';
txt_open_class = 'txt_visible';
txt_closed_class = 'txt_hidden';
top_img_open_src = 'images/box_green_top.gif';
top_img_closed_src = 'images/box_purple_top.gif';
bot_img_open_src = 'images/box_green_bottom.gif';
bot_img_closed_src = 'images/box_purple_bottom.gif';
spacer_open_class = 'box_spacer_open';
spacer_closed_class = 'box_spacer_closed';

open_button_images = new Array('images/button_new_patients_on.gif', 'images/button_pregnancy_info_on.gif', 'images/button_general_gyn_on.gif');
closed_button_images = new Array('images/button_new_patients_off.gif', 'images/button_pregnancy_info_off.gif', 'images/button_general_gyn_off.gif');

num_buttons = 3;

other_preloads = new Array('box_green_bg.gif', 'box_purple_bg.gif', 'button_about_over.gif', 'button_faq_over.gif', 'button_contact_over.gif', 'button_home_over.gif');
preload_prefix = 'images/';
function preload() {
	var pl_img = new Image();

	pl_img.src = top_img_open_src;
	pl_img.src = top_img_closed_src;
	pl_img.src = bot_img_open_src;
	pl_img.src = bot_img_closed_src;

	pl_img.src = 'images/box_green_bg.gif';
	pl_img.src = 'images/box_purple_bg.gif';

	for (var i = 0; i < open_button_images.length; ++i)
		pl_img.src = open_button_images[i];
	for (var i = 0; i < closed_button_images.length; ++i)
		pl_img.src = closed_button_images[i];
	for (var i = 0; i < other_preloads.length; ++i)
		pl_img.src = preload_prefix + other_preloads[i];
}

function toggle_box(id) {
	var idstr = id + '';

	var box_id = 'box_' + idstr;
	var prefix = 'box_' + idstr + '_';
	var txt_id = prefix + 'text';
	var top_img_id = prefix + 'top';
	var bot_img_id = prefix + 'bot';
	var button_id = prefix + 'button';
	var spacer_id = prefix + 'spacer';

	var box = document.getElementById(box_id);
	var txt = document.getElementById(txt_id);
	var top_img = document.getElementById(top_img_id);
	var bot_img = document.getElementById(bot_img_id);
	var button = document.getElementById(button_id);
	var spacer = document.getElementById(spacer_id);

	if (box.className == box_open_class) {
		box.className = box_closed_class;
		txt.className = txt_closed_class;
		top_img.src = top_img_closed_src;
		bot_img.src = bot_img_closed_src;
		button.src = closed_button_images[id];
		spacer.className = spacer_closed_class;
	} else {
		box.className=box_open_class;
		txt.className=txt_open_class;
		top_img.src=top_img_open_src;
		bot_img.src=bot_img_open_src;
		button.src = open_button_images[id];
		spacer.className = spacer_open_class;
	}
}

function swap_image(id, src) {
	var el = document.getElementById(id);
	if (el) {
		el.src = src;
	}
}

nav_img_prefix = 'images/button_';
nav_img_off = new Array('about_off.gif', 'faq_off.gif', 'contact_off.gif', 'home_off.gif');
nav_img_over = new Array('about_over.gif', 'faq_over.gif', 'contact_over.gif', 'home_over.gif');
nav_id_prefix = 'nav_button_';

function nav_hover(num) {
	var el = document.getElementById(nav_id_prefix + num);
	if (!el)
		return;
	el.src = nav_img_prefix + nav_img_over[num];
}

function nav_off(num) {
	var el = document.getElementById(nav_id_prefix + num);
	if (!el)
		return;
	el.src = nav_img_prefix + nav_img_off[num];
}

sub_img_prefix = 'images/sub_';
sub_img_on = '_over';
sub_img_off = '_off';
sub_img_suffix = '.gif';
sub_img_id_prefix = 'sub_img_';

sub_img_bases = new Array('what_to_expect', 'prenatal_screening', 'delivery_time', 'common_procedures', 'medications', 'guidelines', 'timeline');

function toggle_sub_img(num) {
	var el = document.getElementById(sub_img_id_prefix + num);
	if (el.src.indexOf(sub_off_src(num)) != -1) {
		el.src = sub_on_src(num);
	} else {
		el.src = sub_off_src(num);
	}
}

function sub_off_src(num) {
	return sub_img_prefix + sub_img_bases[num] + sub_img_off + sub_img_suffix;
}

function sub_on_src(num) {
	return sub_img_prefix + sub_img_bases[num] + sub_img_on + sub_img_suffix;
}