function ChangeMain(menu) {
	var navA = 'navMainA';
	var navB = 'navMainB';
	 if (document.getElementById) {
	 	if ((document.getElementById(menu).className) == navA) { 
	 	document.getElementById(menu).className = navB;
		}
		else {
			document.getElementById(menu).className = navA;
		}
	 } 
} 
function ChangeSub(menu) {
	var navA = 'navSubA';
	var navB = 'navSubB';
	 if (document.getElementById) {
	 	if ((document.getElementById(menu).className) == navA) { 
	 	document.getElementById(menu).className = navB;
		}
		else {
			document.getElementById(menu).className = navA;
		}
	 } 
} 
function CargarFoto(img, ancho, alto){
  derecha=(screen.width-ancho)/2;
  arriba=(screen.height-alto)/2;
  string="toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=1,width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
  fin=window.open(img,"",string);
}