function mostrar(nombreCapa){ 
document.getElementById(nombreCapa).style.display="block"; 
document.getElementById('avanzadomas').style.display="none";
document.getElementById('avanzadomenos').style.display="inline"; 
} 
function ocultar(nombreCapa){ 
document.getElementById(nombreCapa).style.display="none"; 
document.getElementById('avanzadomas').style.display="inline"; 
document.getElementById('avanzadomenos').style.display="none";
} 

function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}

function MM_jumpMenu(targ,selObj,restore){ //v3.0
  eval(targ+".location='"+selObj.options[selObj.selectedIndex].value+"'");
  if (restore) selObj.selectedIndex=0;
}

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
} 


// Imagenes cabecera
	var imagenumber = 3;
	var randomnumber1 = Math.random() ;
	var randomnumber2 = Math.random() ;
	var randomnumber3 = Math.random() ;
	var rand1 = Math.round( (imagenumber-1) * randomnumber1) + 1 ;
	var rand2 = Math.round( (imagenumber-1) * randomnumber2) + 1 ;
	var rand3 = Math.round( (imagenumber-1) * randomnumber3) + 1 ;