function byId(id)
{
	return document.getElementById(id);
}

function getPageSize()
{
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY)
	{
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	}
	else if (document.body.scrollHeight > document.body.offsetHeight)
	// all but Explorer Mac
	{
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	}
	else
	// Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
	{
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	
	if (self.innerHeight)
	// all except Explorer
	{
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	}
	else if (document.documentElement && document.documentElement.clientHeight)
	// Explorer 6 Strict Mode
	{
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	}
	else if (document.body)
	// other Explorers
	{
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}
	
	// for small pages with total height less then height of the viewport
	if (yScroll < windowHeight)
		pageHeight = windowHeight;
	else
		pageHeight = yScroll;
	
	// for small pages with total width less then width of the viewport
	if (xScroll < windowWidth)
		pageWidth = windowWidth;
	else
		pageWidth = xScroll;
	
	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight)
	return arrayPageSize;
}

function toggleMessageBoxScreen()
{
	if (!byId('MessageBoxScreen'))
	{
		var newNode = document.createElement("div");
		newNode.setAttribute("id", 'MessageBoxScreen');
		newNode.setAttribute("style", "visibility: hidden;");
		document.body.appendChild(newNode);
	}
	
	var MessageBoxScreen = byId('MessageBoxScreen');
	MessageBoxScreen.style.position = "absolute";
	MessageBoxScreen.style.left = "0px";
	MessageBoxScreen.style.top = "0px";
	MessageBoxScreen.style.width = getPageSize()[0] + "px";
	MessageBoxScreen.style.height = getPageSize()[1] + "px";
	MessageBoxScreen.className = "trans75";
	MessageBoxScreen.style.backgroundColor = "#000000";
	MessageBoxScreen.style.zIndex = 9999;
	
	MessageBoxScreen.style.visibility = (MessageBoxScreen.style.visibility == "visible" ? "hidden" : "visible");
	MessageBoxScreen.style.display = (MessageBoxScreen.style.display == "block" ? "none" : "block");
}