var detectedUA = navigator.userAgent.toLowerCase();
var browser, loc;
var firstrun = true;

function strCheck(string) {
	loc = detectedUA.indexOf(string) + 1;
	thestring = string;
	return loc;
}

if (strCheck('konqueror')) browser = "Konqueror";
else if (strCheck('safari')) browser = "Safari";
else if (strCheck('omniweb')) browser = "OmniWeb";
else if (strCheck('opera')) browser = "Opera";
else if (strCheck('webtv')) browser = "WebTV";
else if (strCheck('icab')) browser = "iCab";
else if (strCheck('msie 7.0')) browser = "IE7";
else if (strCheck('msie 6.0')) browser = "IE6";
else if (!strCheck('compatible')) browser = "Netscape Navigator";
else browser = "An unknown browser";

function getDim(el) {
	for (var lx = 0, ly = 0; el != null; lx += el.offsetLeft, ly += el.offsetTop, el = el.offsetParent);
	return {x:lx,y:ly}
}

function setOverlayImage(elm) {
	if (elm) {
		var imgContainer = document.getElementById('overlay_content');
		if (imgContainer) {
			imgContainer.innerHTML = '<img src="' + elm.href + '" onclick="hideGalleryOverlay();" alt="' + elm.alt + '" />';
		}
	}
}

function showGalleryOverlay(elm) {
	var overlay_elm = document.getElementById('gallery_overlay_module');
	var cloak_elm = document.getElementById('overlay_cloak');
	var thumbElm = elm.getElementsByTagName('img')[0];
	var closeElm = document.getElementById('close_overlay_info');
	var imgContainer = document.getElementById('overlay_content');
	var iewidth = 0;
	var ie6 = (browser == "IE6") ? true : false;
	var ie7 = (browser == "IE7") ? true : false;
	
	var imgAlt = thumbElm.alt;
	
	if (cloak_elm) {
		var height = document.body.offsetHeight;
		var width = "100%";
		
		if (ie6) {
			iewidth = (document.documentElement.offsetWidth - 17) + "px";
			if (closeElm) {
				closeElm.style.display = "none";
			}
		}
		
		cloak_elm.style.height = height + "px";
		if (ie6) {
			cloak_elm.style.width = iewidth;
		} else {
			cloak_elm.style.width = width;
		}
		
		cloak_elm.style.visibility = "visible";
	}
	
	if (imgContainer) {
		imgContainer.innerHTML = '<img src="' + elm.href + '" onclick="hideGalleryOverlay();" alt="' + imgAlt + '" />';
	}
	
	var curScrollX = (typeof window.pageXOffset != 'undefined') ? window.pageXOffset : document.documentElement.scrollLeft;
	var innerW = (typeof self.innerWidth != 'undefined') ? self.innerWidth : document.documentElement.clientWidth;
	overlay_elm.style.left = Math.ceil((innerW - overlay_elm.offsetWidth)/2)+curScrollX+"px";

	var curScrollY = (typeof window.pageYOffset != 'undefined') ? window.pageYOffset : document.documentElement.scrollTop;
	var innerH = (typeof self.innerHeight != 'undefined') ? self.innerHeight : document.documentElement.clientHeight;
	
	overlay_elm.style.top = Math.ceil((innerH - overlay_elm.offsetHeight)/2)+curScrollY + "px";
	
	if ((ie6 || ie7) && firstrun) overlay_elm.style.left = (document.documentElement.clientWidth/2) - (overlay_elm.offsetWidth/2) + "px";
	
	overlay_elm.style.visibility = "visible";
	overlay_elm = null;
	firstrun = false;
}

function hideGalleryOverlay() {
	var elm = document.getElementById('gallery_overlay_module');
	if (elm) {
		elm.style.visibility = "hidden";
	}
	var cloak_elm = document.getElementById('overlay_cloak');
	if (cloak_elm) cloak_elm.style.visibility = "hidden";
}