// Browser Window Size and Position
// copyright Stephen Chapman, 3rd Jan 2005, 8th Dec 2005
// you may copy these functions but please keep the copyright notice as well
function pageWidth() 
{
	return window.innerWidth != null? window.innerWidth : document.documentElement && document.documentElement.clientWidth ?       document.documentElement.clientWidth : document.body != null ? document.body.clientWidth : null;
} 

function pageHeight() 
{
	return  window.innerHeight != null? window.innerHeight : document.documentElement && document.documentElement.clientHeight ?  document.documentElement.clientHeight : document.body != null? document.body.clientHeight : null;
} 

function posLeft() 
{
	return typeof window.pageXOffset != 'undefined' ? window.pageXOffset :document.documentElement && document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft ? document.body.scrollLeft : 0;
} 

function posTop() 
{
	return typeof window.pageYOffset != 'undefined' ?  window.pageYOffset : document.documentElement && document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop ? document.body.scrollTop : 0;
} 

function posRight() 
{
	return posLeft()+pageWidth();
} 

function posBottom() 
{
	return posTop()+pageHeight();
}


function scaleBackground()
{
	while (document.getElementById('inhoud').bottom < posBottom())
	{
		document.getElementById('inhoud').innerHeight++;
	}
}

function _Convert(val) 
	{
		if (!val) {return;}
		val = val.replace("px","");
		if (isNaN(val)) {return 0;}
		return parseInt(val);
	}


function getHeight(elem) 
{
	var currentStyle;
	if (elem.currentStyle) { currentStyle = elem.currentStyle; }
	else if (window.getComputedStyle) {	currentStyle = document.defaultView.getComputedStyle(elem, null); }
	else { currentStyle = elem.style; }
	return (elem.offsetHeight -
		_Convert(currentStyle.marginTop) -
		_Convert(currentStyle.marginBottom) -
		_Convert(currentStyle.borderTopWidth) -
		_Convert(currentStyle.borderBottomWidth));	
}