function decrease(){
	var body;
	body	= document.getElementsByTagName("body")[0];
	actualSize	= parseInt(body.className.split("size")[1]);
	actualSize	= isNaN(actualSize) ? 0 : actualSize;
	size		= actualSize -1 <= 0 ? 0 : actualSize -1;
	body.className = "size" + size;
}
function increase(){
	var body;
	body	= document.getElementsByTagName("body")[0];
	actualSize	= parseInt(body.className.split("size")[1]);
	actualSize	= isNaN(actualSize) ? 0 : actualSize;
	size		= actualSize + 1 >= 3 ? 3 : actualSize + 1;
	body.className = "size" + size;
}