var activa=null;function nl(){}
function mc(nombrecapa)
 {
	if (document.layers) {objeto=document.layers[nombrecapa];}
	else if (document.all && !document.getElementById) {objeto=eval(document.all[nombrecapa]);}
	else {objeto=eval(document.getElementById(nombrecapa));}
	if (objeto.style.display=="none")
	 {
		if (activa!=null){activa.display="none";}
		objeto.style.display="block";
		activa=eval(objeto.style);
	 }
	else{objeto.style.display="none"; }
 }

 function ventana(cad,an,al){ancho = screen.width; alto = screen.height; mitada = (ancho - an) / 2; mitadb = (alto - al) / 2;window.open(cad,"","width="+an+",height="+al+",screenX="+mitada+",screenY="+mitadb+",top="+mitadb+",left="+mitada+",scrollbars=1,titlebar=1,menubar=1,status=1,toolbar=1");}