/* Show next image when clicked on thumbnail image */
function next_image_thumb(image) {
       if(!image) return;
       document.getElementById("img_det").src = image;
}

function validarEmail(cadena) {
  var a = cadena.value;
  var filter=/^[A-Za-z][A-Za-z0-9_]*@[A-Za-z0-9_]+.[A-Za-z0-9_.]+[A-za-z]$/;
  if (a.length == 0 )
  return true;

  if (filter.test(a))
  return true;
  else {
    alert("Por favor, debe ingresar un email correcto");
    cadena.value="";
    cadena.focus();
    return false;
  }
}


function bloquear() {
form_contacto.submit.disabled = true;
form_contacto.submit.value = "Enviando datos... ";
}