function capa1_mostrar(){ 
document.getElementById("noticias").style.visibility="visible"; 
} 
function capa1_ocultar(){ 
document.getElementById("noticias").style.visibility="hidden"; 
} 

function capa2_mostrar(){ 
document.getElementById("productos").style.visibility="visible"; 
} 
function capa2_ocultar(){ 
document.getElementById("productos").style.visibility="hidden"; 
}