function getScrollPos()
{
	var ScrollTop = document.body.scrollTop;

	if (ScrollTop == 0)
	{
	    if (window.pageYOffset)
	        ScrollTop = window.pageYOffset;
	    else
	        ScrollTop = (document.body.parentElement) ? document.body.parentElement.scrollTop : 0;
	}
	return ScrollTop;
	
}



function showTop()
{
	// for IE6.0    
	if ((BrowserDetect.browser == "Explorer") && (BrowserDetect.version<7))
	{
		if (document.body.clientHeight > document.documentElement.clientHeight )
		{
			document.getElementById('screenoverlay').style.height = document.body.clientHeight;
		}
		else {
			document.getElementById('screenoverlay').style.height = document.documentElement.clientHeight;
		}

		if (document.body.clientWidth > document.documentElement.clientWidth )
		{
			document.getElementById('screenoverlay').style.width = document.body.clientWidth;
		}
		else {
			document.getElementById('screenoverlay').style.width = document.documentElement.clientWidth;
		}
	}  

	//Show the background overlay and topbox...
	document.getElementById('screenoverlay').style.visibility = 'visible';
	document.getElementById('topbox').style.display = 'block';
	
	centerElementOnScreen('topbox');
}


function scrollEvent()
{
	centerElementOnScreen('topbox');
}


function closeTop()
{
	//Hide the overlay and tobox...
	document.getElementById('screenoverlay').style.visibility = 'hidden';
	document.getElementById('topbox').style.display = 'none';
}     

function getViewportSize(side)
{
	var viewportWidth;
	var viewportHeight;

	// for standards compliant browsers (mozilla/netscape/opera/IE7)     
	if (typeof window.innerWidth != 'undefined')
	{
		viewportWidth = window.innerWidth,
		viewportHeight = window.innerHeight
	}        
	// IE6 in standards compliant mode (i.e. with a valid doctype)    
	else if (typeof document.documentElement != 'undefined' && typeof document.documentElement.clientWidth != 'undefined' && document.documentElement.clientWidth != 0)
	{
		viewportWidth = document.documentElement.clientWidth,
		viewportHeight = document.documentElement.clientHeight
	}        
	// older versions of IE
	else
	{
		viewportWidth = document.getElementsByTagName('body')[0].clientWidth,
		viewportHeight = document.getElementsByTagName('body')[0].clientHeight
	}  

	return (side == 'width' ? viewportWidth : viewportHeight);
} 

window.onresize = scrollEvent;
window.onscroll = scrollEvent;

function centerElementOnScreen(id)
{
	var elementHeight=document.getElementById(id).offsetHeight;
	var elementWidth=document.getElementById(id).offsetWidth;

	document.getElementById(id).style.top = (getViewportSize('height')-elementHeight)/2 + getScrollPos() +"px";
	document.getElementById(id).style.left = (getViewportSize('width')-elementWidth)/2+"px";        
}

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);
}

function showTopDelayed(seconds)
{
	setTimeout(showTop,seconds*1000);
}

function showTopDelayedOncePerDay(seconds)
{
	if (readCookie("lightbox") =="1")
	{
		
	}
	else
	{
		createCookie("lightbox","1","1");
		setTimeout(showTop,seconds*1000);
	}
}