/*	Overlay

	Technique taken from 
		Lightbox JS: Fullsize Image Overlays 
		by Lokesh Dhakar - http://www.huddletogether.com
	
		For more information on this script, visit:
		http://huddletogether.com/projects/lightbox/
*/

function InitOverlay() {
	// the rest of this code inserts html at the top of the page that looks like this:
	//
	// <div id="overlay">
	//		<a href="#" onclick="hideLightbox(); return false;"><img id="loadingImage" /></a>
	//	</div>
	
	//var objBody = document.getElementsByTagName("body").item(0);
	var objOverlay = document.getElementById('overlay');
	
	// create overlay div and hardcode some functional styles (aesthetic styles are in CSS file)
	var objOverlay = document.createElement("div");
	objOverlay.setAttribute('id','overlay');
	objOverlay.style.display = 'none';
	objOverlay.style.position = 'absolute';
	objOverlay.style.top = '0px';
	objOverlay.style.left = '0';
	objOverlay.style.zIndex = '90';
 	objOverlay.style.width = '100%';
 	objOverlay.style.height = '100%';
 	//objBody.insertBefore(objOverlay, objBody.firstChild);
	
	//	Insert into mapview
	var e = document.getElementById('mapview');
	e.insertBefore(objOverlay, e.firstChild);
}

function ShowOverlay() {
	// prep objects
	var objOverlay = document.getElementById('overlay');
	var arrayPageSize = getPageSize();
//alert('showing overlay');
	// set height of Overlay to take up whole page and show
//	objOverlay.style.height = '500px';
	objOverlay.style.height = (arrayPageSize[1] + 'px');
	objOverlay.style.display = 'block';
}

function HideOverlay() {
	// get objects
	objOverlay = document.getElementById('overlay');

	// hide overlay
	objOverlay.style.display = 'none';
}

//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize(){
	
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if (yScroll < windowHeight) {
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

	// for small pages with total width less then width of the viewport
	if (xScroll < windowWidth) {	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}


	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
	return arrayPageSize;
}

//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll(){

	var yScroll;

	if (self.pageYOffset) {
		yScroll = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop) {	 // Explorer 6 Strict
		yScroll = document.documentElement.scrollTop;
	} else if (document.body) {// all other Explorers
		yScroll = document.body.scrollTop;
	}

	arrayPageScroll = new Array('',yScroll) 
	return arrayPageScroll;
}