function centrePage()
{
	var theBrowserHeight = getBrowserHeight();
	var theCanvas = document.getElementById("canvas");
	var theContentHeight = 561;
	var theVertical = document.getElementById("verticalCentre");

	if (theContentHeight > theBrowserHeight)
	{
		theVertical.className = "top";
	}
	else
	{
		theVertical.className = "";
	}
	
	return true;
}



function getBrowserHeight()
{
	if (window.innerHeight)
	{
		return window.innerHeight;
	}
	else if (document.documentElement && document.documentElement.clientHeight != 0)
	{
		return document.documentElement.clientHeight;
	}
	else if (document.body)
	{
		return document.body.clientHeight;
	}
	
	return false;
}