/*
	** Cookie cutting code by PPK: quirksmode.org
	*/

	function createCookie(name,value,days) {
		if (days) {
			var date = new Date();
			date.setTime(date.getTime()+(days*24*60*60*1000));
			var expires = "; expires="+date.toGMTString();
		}
		else var expires = "";
		document.cookie = name+"="+value+expires+"; path=/";
	}

	function readCookie(name) {
		var nameEQ = name + "=";
		var ca = document.cookie.split(';');
		for(var i=0;i < ca.length;i++) {
			var c = ca[i];
			while (c.charAt(0)==' ') c = c.substring(1,c.length);
			if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
		}
		return null;
	}

	function eraseCookie(name) {
		createCookie(name,"",-1);
	}

	/*
	** Make external links open in a new window
	*/

	function externalLinks() {
		if (!document.getElementsByTagName) return;
		var anchors = document.getElementsByTagName("a");
		for (var i=0; i < anchors.length; i++) {
			var anchor = anchors[i];
			if (anchor.getAttribute("href") && anchor.getAttribute("rel") == "external") {
				anchor.target = "_blank";
			}
		}
	}

	function validateEmail() {

		var messageBox = document.getElementById("signup-message");
		var messageText = messageBox.getElementsByTagName("span")[0].firstChild;
		var submitButton = document.getElementById("signup-submit");
		var email = document.getElementById("signup-email-input").value;
		if (isValidEmail(email)) {
			submitButton.disabled = false;
			messageText.data = "";
			messageBox.className = "accepted";
		} else if (email == "") {
			messageText.data = "Please enter your email address to continue.";
			submitButton.disabled = true;
			messageBox.className = "alert";
		} else if (email != "") {
			messageText.data = "This email address is not formed properly. Please enter a valid email address to continue.";
			submitButton.disabled = true;
			messageBox.className = "alert";
		}

	}

	function isValidEmail(address) {
		return (/^(\w[-\w'\.]*\w|"[^"\\\n]+")@(\w+[-\w\.]*\.[-\w]{2,})$/).test(address);
	}

	window.onload =
	function() {
		externalLinks();

		// validate email
		if (document.getElementById) {
			if (document.getElementById("signup-submit")) {
				validateEmail();
				document.getElementById("signup-email-input").onblur =
						validateEmail;
				document.getElementById("signup-email-input").onkeyup =
						validateEmail;
			}
		}


		//banner fading
		var bannerImage = $$("#header img")[0];
		if (readCookie("bannerFade") != "played") {
			fadeSwitchImage(bannerImage, bannerImage.src.replace(/[^\/]+$/,"LD-transition-logo.gif"),
					$$("#header img")[0].src)
			createCookie("bannerFade", "played", 5);
		}
	}


	/*
	** Fade and switch images
	*/

	function fadeSwitchImage(image, fromSrc, toSrc)
	{
		if (image) {
			Opacity(image, {
				from: 1,
				to: 0,
				duration: 1,
				beforeStart: function() {
					image.src = fromSrc;
				},
				afterFinish: function() {
					image.src = toSrc;
					Opacity(image, {
						from: 0,
						to: 1,
						duration: 2
					});
				}
			});
		}
	}

	function openLinkInPopup(heigthPercent, widthPercent){
		var _defaultHeightPercent = 60;
		var _defaultWidthPercent = 50;
		var _h = typeof heigthPercent != "undefined"?heigthPercent:_defaultHeightPercent;
		var _w = typeof widthPercent != "undefined"?widthPercent:_defaultWidthPercent;	
		openPopup(this.href, _h, _w);
		return false;
	}

	/*
	** Opens a popup with specified height/width
	*/

	function openPopup(url,heigthPercent, widthPercent, features)
	{
		var _popupName = "";
		var _defaultHeightPercent = 80;
		var _defaultWidthPercent = 75;
		var _h = screen.height * (typeof heigthPercent != "undefined"?heigthPercent:_defaultHeightPercent) / 100;
		var _w = screen.width * (typeof widthPercent != "undefined"?widthPercent:_defaultWidthPercent) /100;
		var _features = (typeof features != "undefined"?features:"resizable=no,toolbar=no,menubar=no,location=no,scrollbars=yes");
		var _settings= "";
		var _winl;
		var _wint;
		if(screen.width) {
			_winl = (screen.width-_w)/2;
			_wint = (screen.height-_h)/2 - 50;
		}else {
			_winl = 0;
			_wint = 0;
		}

		if(_winl < 0) _winl = 0;
		if(_wint < 0) _wint = 0;

		_settings += "height=" + _h + ",";
		_settings += "width=" + _w + ",";
		_settings += "top=" + _wint + ",";
		_settings += "left=" + _winl + ",";
		_settings += _features;
		window.open(url,_popupName,_settings).focus();
	}