function toggleOverlay(state)
{
	if(document.getElementById) {
		document.getElementById('shadePane').style.display = state;
		document.getElementById('overlayPane').style.display = state;
	}
	else if(document.all) {
		document.all['shadePane'].style.display = state;
		document.all['overlayPane'].style.display = state;
	}
}

function setContent(content)
{
	if(document.getElementById) {
		document.getElementById('overlayPane').innerHTML = content;
	}
	else if(document.all) {
		document.all.overlayPane.innerHTML = content;
	}
}

function centerPane()
{
	if(! window.innerWidth) {
		if(! (document.documentElement.clientWidth == 0)) {
			w = document.documentElement.clientWidth;
		}
		else {
			w = document.body.clientWidth;
		}
	}
	else {
		w = window.innerWidth;
	}

	if(document.getElementById) {
		obj = document.getElementById("overlayPane");
	}
	else if(document.all) {
		obj = document.all.overlayPane;
	}

	to = parseInt((w / 2) - (obj.offsetWidth / 2));
	obj.style.margin = 0;

	if(obj.offsetLeft != to) {
		obj.style.left = parseInt((obj.offsetLeft + to) / 2) + "px";
		setTimeout("centerPane();", 100);
	}
}

function displayMedia(file, list)
{
	var request = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("MSXML2.XMLHTTP.3.0");
	request.open("GET", "../mdb/present.php?file=" + file + "&list=" + list, true);
	request.onreadystatechange = function() {
		if(request.readyState == 4 && request.status == 200) { 
			if(request.responseText) {
				setContent(request.responseText);
				setTimeout("centerPane();", 500);
			}
		}
	};
	request.send(null);
}

function setOpacity(level)
{
	if(document.getElementById) {
		document.getElementById('overlayPane').style.opacity = level / 100;
	}
	else if(document.all) {
		document.all['overlayPane'].style.filter = "alpha(opacity=" + level + ");";
	}
}

function fadeIn(level)
{
	setOpacity(level);
	if(level < 100) {
		level += 20;
		setTimeout("fadeIn(" + level + ");", 20);
	}
}

function fadeOut(level)
{
	setOpacity(level);
	if(level > 0) {
		level -= 20;
		setTimeout("fadeOut(" + level + ");", 20);
	}
	else {
		toggleOverlay('none');
	}
}