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/desarrolloLocal.gif","images/menu/desarrolloLocalBis.gif","images/menu/juventud.gif","images/menu/juventudBis.gif","images/menu/servSociales.gif","images/menu/servSocialesBis.gif","images/menu/cultura.gif","images/menu/culturaBis.gif","images/menu/biblioteca.gif","images/menu/bibliotecaBis.gif","images/menu/deportes.gif","images/menu/deportesBis.gif","images/menu/servTecnicos.gif","images/menu/servTecnicosBis.gif","images/menu/oficinaJudicial.gif","images/menu/oficinaJudicialBis.gif","images/menu/eduInfancia.gif","images/menu/eduInfanciaBis.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["capa"].document.images[nombre].src = lista_imagenes[parseInt(index)].src;
    }
}