function GetZoomFactor() {
 	var factor = 1;
 	if (document.body.getBoundingClientRect) {
		// rect is only in physical pixel size in IE before version 8 
		var rect = document.body.getBoundingClientRect();
		var physicalW = rect.right - rect.left;
		var logicalW = document.body.offsetWidth;

		// the zoom level is always an integer percent value
		factor = Math.round ((physicalW / logicalW) * 100) / 100;
 	}
 	return factor;
}

function GetWindowSize() {
	var zoomFactor = GetZoomFactor();
	var h = Math.round (document.documentElement.clientHeight / zoomFactor) - 25;
	var queAltura = document.getElementById("altura");
	queAltura.style.height = h + "px";
	queAltura.style.overflow = "auto";

	mueveMenu('moverMenu');
}

function mueveMenu(queMenu){
	var capas = queMenu.split("-");
	for(x=0;x<capas.length;x++) {
		$(capas[x]).animate({
				"left": "-=18em"
				}, 800
		);								 										 
	}
}