var nav = navigator
browserIE = ((nav.appName == "Microsoft Internet Explorer") && (parseInt(nav.appVersion) >= 4 ))
browserNS1 = ((nav.appName == "Netscape") && (parseInt(nav.appVersion) < 5 ) ) // Netscape < 4.7
browserNS2 = ((nav.appName == "Netscape") && (parseInt(nav.appVersion) >= 5 ) )// Netscape >= 6

// Precarga de imágenes ----------------------------------------
var i;
var imagenes = new Array("images/menu/bienvenida.gif","images/menu/bienvenidaBis.gif","images/menu/quienes.gif","images/menu/quienesBis.gif","images/menu/dondeEstamos.gif","images/menu/dondeEstamosBis.gif","images/menu/comunicados.gif","images/menu/comunicadosBis.gif","images/menu/ficha.gif","images/menu/fichaBis.gif","images/menu/hylogos.gif","images/menu/hylogosBis.gif","images/menu/generaciones.gif","images/menu/generacionesBis.gif","images/menu/informacion.gif","images/menu/informacionBis.gif","images/menu/concejales.gif","images/menu/concejalesBis.gif","images/menu/proyectos.gif","images/menu/proyectosBis.gif");
var lista_imagenes = new Array();
function cargarimagenes(){
for(i in imagenes){
lista_imagenes[i] = new Image();
lista_imagenes[i].src = imagenes[i];
}
}

function cambio(nombre,index){
    if ((browserIE)||(browserNS2))
	{
		document.images[nombre].src = lista_imagenes[parseInt(index)].src;

    }
    else if (browserNS1)
	{
		document.layers["upc3"].document.images[nombre].src = lista_imagenes[parseInt(index)].src;
    }
}