

<!-- // Formulario

function enviar_frm_contacta()
{
	error_message = "";
	
    if (document.frm_contacta.email.value.length==0)
	{
    	error_message = "- E-mail\n" + error_message;
    	document.frm_contacta.email.focus();
		document.frm_contacta.email.select();
    }

	if (document.frm_contacta.nombre.value.length==0)
	{
    	error_message = "- Nombre\n" + error_message;
    	document.frm_contacta.nombre.focus();
		document.frm_contacta.nombre.select();
    }

	if (error_message != "")
	{
		error_message = "Los siguientes campos son obligatorios:\n\n" + error_message;
		window.alert(error_message);
		return;
	}
	
	length_mail = document.frm_contacta.email.value.length;
	length_mail = length_mail - 1;
	if ( (document.frm_contacta.email.value.indexOf ('@', 0) < 1) || (document.frm_contacta.email.value.length < 5) 
		|| (document.frm_contacta.email.value.lastIndexOf(".") < 2) || (document.frm_contacta.email.value.charAt(length_mail) == "." ) )
	{ 
    	alert("Escriba una dirección de correo válida en el campo \"E-mail\".");
		document.frm_contacta.email.focus();
		document.frm_contacta.email.select();
    	return;
    }
    
	document.frm_contacta.submit();
	
}

<!-- // Mostrar ocultar capas	

var visto = null;
function verCapa(iden) {
  obj = document.getElementById(iden);
  if (obj==visto) return false;
  if (visto!=null)
    visto.style.visibility = 'hidden';
  obj.style.visibility = 'visible';
  visto=obj;
}

var visto1 = null;
function verCapa1(iden) {
  obj = document.getElementById(iden);
  if (obj==visto1) return false;
  if (visto1!=null)
    visto1.style.visibility = 'hidden';
  obj.style.visibility = 'visible';
  visto1=obj;
}


  if (document.images) {

     var txt_contactooff = new Image()
     txt_contactooff.src = "img/txt_contactooff.jpg"
     var txt_contactoon = new Image()
     txt_contactoon.src = "img/txt_contactoon.jpg"

     var txt_quienoff = new Image()
     txt_quienoff.src = "img/txt_quienoff.jpg"
     var txt_quienon = new Image()
     txt_quienon.src = "img/txt_quienon.jpg"
	 
	 var txt_expooff = new Image()
     txt_expooff.src = "img/txt_expooff.jpg"
     var txt_expoon = new Image()
     txt_expoon.src = "img/txt_expoon.jpg"
	 
	 var txt_obraoff = new Image()
     txt_obraoff.src = "img/txt_obraoff.jpg"
     var txt_obraon = new Image()
     txt_obraon.src = "img/txt_obraon.jpg"

   
  }
                function inact(imgName) {
                if (document.images)
                  document[imgName].src = eval(imgName+'off.src')
                }
               function act(imgName) {
                if (document.images) 
                  document[imgName].src = eval(imgName+'on.src')
              }