// JavaScript Document
function getViewportSize() { 
	var x, y; 
	if (self.innerHeight) { // MOS 
		y = self.innerHeight; 
		x = self.innerWidth; 
	} else if (
		document.documentElement && document.documentElement.clientWidth) { // IE6 Strict 
		x = document.documentElement.clientWidth; 
		y = document.documentElement.clientHeight; 
	} else if (
		document.body.clientHeight) { // IE quirks 
		y = document.body.clientHeight; 
		x = document.body.clientWidth; 
	} 
	return {x: x, y: y}; 
} 
function Centrar() {
	var capa = document.getElementById("content");
	alto = document.body.clientHeight;
	if (getViewportSize().y > 480) {
		capa.className = "centered";
	} else {
		capa.className = null;
	}
}
onload= Centrar;
onresize= Centrar;