function zmenitvelikost ()
{
 	var x = document.getElementById ('box');
	if (document.body.clientHeight > document.body.scrollHeight)
	{
		x.style.height = document.body.clientHeight;
	}
	else
	{
		x.style.height = document.body.scrollHeight;
	}
	
	var x = document.getElementById ('box');
	
	if (document.body.clientWidth < 800)
	{
		x.style.marginLeft = - (document.body.clientWidth / 2);
	}
	
	
}