/* Monthly Admin Explanation */

/* preload close buttons */
var img1 = new Image();
img1.src = "images/close_button.jpg";
var img2 = new Image();
img2.src = "images/close_button_hover.jpg";

/* opacity for fade-in */
var opac = 0;

function displayOverlay(url)
{
	var overlay_bg = document.createElement("div");
	overlay_bg.setAttribute("id", "overlay_bg");
	var overlay_fg = document.createElement("div");
	overlay_fg.setAttribute("id", "overlay_fg");
	overlay_fg.innerHTML = "<a href='javascript:void();' onclick='fadeOut();'  style='float:right'><img src='images/close_button.jpg' onmouseover='overCloseButton(this);' onmouseout='outCloseButton(this);'></a>";
	document.body.appendChild(overlay_bg);
	document.body.appendChild(overlay_fg);

	var req = createRequest();
	req.open("GET", url, true);
	req.send(null);

	req.onreadystatechange = function()
	{
		if (req.readyState == 4)
		{
			if (req.status == 200)
			{
				var html = req.responseText;
				overlay_fg.innerHTML = overlay_fg.innerHTML + html;

				fadeIn();
			}
		}
	}
}

function removeUpdatesExpl()
{
	var overlay_bg = document.getElementById("overlay_bg");
	document.body.removeChild(overlay_bg);
	var overlay_fg = document.getElementById("overlay_fg");
	document.body.removeChild(overlay_fg);
}

function createRequest()
{
	var req;
	
	try
	{
		req = new XMLHttpRequest();
	}
	catch (e)
	{
		try
		{
			req = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			req = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}

	
	return req;

}

function outCloseButton(image)
{
	image.src = img1.src;
}

function overCloseButton(image)
{
	image.src = img2.src;
}


function fadeIn()
{
	var bg = document.getElementById("overlay_bg");
	var fg = document.getElementById("overlay_fg");
	var currentMozOpac = bg.style.MozOpacity * 10;
	if (currentMozOpac >= 9)
		return;

	opac ++;
	bg.style.opacity = opac / 10;
	bg.style.MozOpacity = opac / 10;
	bg.style.filter = "alpha(opacity=" + (opac * 10) + ")";

	fg.style.opacity = opac / 10;
	fg.style.MozOpacity = opac / 10;
	fg.style.filter = "alpha(opacity=" + (opac * 10) + ")";

	setTimeout("fadeIn()", 50);

}

function fadeOut()
{
	var bg = document.getElementById("overlay_bg");
	var fg = document.getElementById("overlay_fg");
	var currentMozOpac = bg.style.MozOpacity * 10;
	if (currentMozOpac <= 0)
	{
		removeUpdatesExpl();
		return;
	}

	opac --;
	bg.style.opacity = opac / 10;
	bg.style.MozOpacity = opac / 10;
	bg.style.filter = "alpha(opacity=" + (opac * 10) + ")";

	fg.style.opacity = opac / 10;
	fg.style.MozOpacity = opac / 10;
	fg.style.filter = "alpha(opacity=" + (opac * 10) + ")";

	setTimeout("fadeOut()", 50);

}