var PopupWindow = {
	hideAll: function()
	{
		popupWindows = document.getElementsByClassName('popup');
		
		popupWindows.each
		(
			function(box)
			{
				Element.hide(box);
			} // function
		) // each

		if ($('overlay'))
		{
			Element.remove('overlay');
		} // if
	} // hideAll()
} // PopupWindow

PopupWindow.base = Class.create();

PopupWindow.base.prototype = {
	initialize: function(element, options)
	{
		// first off, hide all popup windows
		PopupWindow.hideAll();
	
		this.element = $(element);

		this.options = Object.extend
		( { popupClassName : 'popup'
			, closeOnOverlayClick : false
			, externalControl : false
			}
		, options || {}
		)

		// create the full-page overlay
		new Insertion.Before(this.element, "<div id='overlay' style='display:none;'></div>");
		Element.addClassName(this.element, this.options.popupClassName);

		// add an popup class to the element so we can close all pop-up quickly
		Element.addClassName(this.element, 'popup');
		
		if (this.options.closeOnOverlayClick)
		{
			Event.observe($('overlay'), 'click', this.hidePopupWindow.bindAsEventListener(this));
		} // if
		
		if (this.options.externalControl)
		{
			Event.observe($(this.options.externalControl), 'click', this.hidePopupWindow.bindAsEventListener(this));
		} // if

		if (this.options.okControl)
		{
			Event.observe($(this.options.okControl), 'click', this.hidePopupWindow.bindAsEventListener(this));
		} // if

		this.showPopupWindow();	
	}, // initialize()
	
	
	showPopupWindow : function()
	{
		// show the overlay
		Element.show('overlay');

		// center the popup window
		this.center();

		// show the popup window
		new Effect.Appear(this.element, {duration: .2});

		return false;
	}, // showPopupWindow()
	
	
	hidePopupWindow : function(evt)
	{
		// remove the popup window class we added when showing the window
		Element.removeClassName(this.element, this.options.popupClassName);

		// hide the popup window
		Element.hide(this.element);

		// remove the overlay DIV
		Element.remove('overlay');

		return false;
	}, // hidePopupWindow()
		
	center : function()
	{
		var my_width  = 0;
		var my_height = 0;
		
		if (typeof(window.innerWidth) == 'number')
		{
			my_width  = window.innerWidth;
			my_height = window.innerHeight;
		} // if
		else if (document.documentElement && (document.documentElement.clientWidth || document.documentElement.clientHeight))
		{
			my_width  = document.documentElement.clientWidth;
			my_height = document.documentElement.clientHeight;
		} // else if
		else if (document.body && (document.body.clientWidth || document.body.clientHeight))
		{
			my_width  = document.body.clientWidth;
			my_height = document.body.clientHeight;
		} // else if

		this.element.style.position = 'absolute';
		this.element.style.zIndex = 99;

		var scrollY = 0;

		if (document.documentElement && document.documentElement.scrollTop)
		{
			scrollY = document.documentElement.scrollTop;
		} // if
		else if (document.body && document.body.scrollTop)
		{
			scrollY = document.body.scrollTop;
		} // else if
		else if (window.pageYOffset)
		{
			scrollY = window.pageYOffset;
		} // else if
		else if (window.scrollY)
		{
			scrollY = window.scrollY;
		} // else if
		
		var elementDimensions = Element.getDimensions(this.element);
		
		var setX = (my_width  - elementDimensions.width) / 2;
		var setY = (my_height - elementDimensions.height) / 2 + scrollY;
		
		setX = (setX < 0) ? 0 : setX;
		setY = (setY < 0) ? 0 : setY;
		
		this.element.style.left = setX + "px";
		this.element.style.top  = setY + "px";
	} // center()
} // PopupWindow


function showPopupWindow(parentId, popupId, focusId)
{
	new PopupWindow.base(popupId);

	document.forms[0][focusId].focus();
} // showPopupWindow()


function hidePopupWindow(popupId)
{
	new Effect.Fade($(popupId), {duration: .2});
} // hidePopupWindow()