function $() {
	var elements = new Array();
	for (var i = 0; i < arguments.length; i++) {
		var element = arguments[i];
		if (typeof element == 'string')
			element = document.getElementById(element);
		if (arguments.length == 1)
			return element;
		elements.push(element);
	}
	return elements;
}

function toggleVideoPopup(dm, id) {
	toggleWindowShade(dm);
	toggleVideoDisplay(id);
}
function toggleWindowShade(displayMode) { // block or none
	element = document.getElementById('windowshade');
	if (!element || element.style.display == displayMode)
		return;
	if (displayMode == 'block') {
		var biggestHeight = document.body.scrollHeight;
		if (getWinHeight() > biggestHeight)
			biggestHeight = getWinHeight();

		element.style.width=document.body.scrollWidth+'px';
		element.style.height=biggestHeight+'px';
	}
	element.style.display = displayMode;
}

function toggleVideoDisplay(id) { // visible or hidden
	if (id=='all') {
		document.getElementById('video-1').style.display = 'none';
		document.getElementById('video-2').style.display = 'none';
		document.getElementById('video-3').style.display = 'none';
		document.getElementById('audio').style.display = 'block';
	} else {
		element = document.getElementById(id);
		if (!element) {	return; }
		if (element.style.display == 'block') {
			element.style.display = 'none';
			document.getElementById('audio').style.display = 'block';
		} else {
			element.style.display = 'block';
			document.getElementById('audio').style.display = 'none';
		}
		
		var pageWidth = document.body.scrollWidth;
		var xOffset = element.offsetWidth/2;
		element.style.left = (pageWidth/2)-xOffset+"px";
	}
}

function getWinHeight()
{
    if (window.innerHeight) return window.innerHeight;
  	else if (document.documentElement && document.documentElement.clientHeight) 
  		return document.documentElement.clientHeight;
  	else if (document.body && document.body.clientHeight) 
  		return document.body.clientHeight;
  	else if (document.body && document.body.parentNode && document.body.parentNode.clientHeight) 
  		return document.body.parentNode.clientHeight;
}