function checkForm(form)
{

  if (form.name.value == "")
  {
    alert("Please insert your name.");
    form.name.focus();
    return (false);
  }
  
   if (form.surname.value == "")
  {
    alert("Please insert your surname.");
    form.surname.focus();
    return (false);
  }

  if (form.street.value == "")
  {
    alert("Please insert the address.");
    form.street.focus();
    return (false);
  }

  if (form.postcode_town.value == "")
  {
    alert("Please insert the town.");
    form.postcode_town.focus();
    return (false);
  }
  
   if (form.country.value == "")
  {
    alert("Please insert the country.");
    form.country.focus();
    return (false);
  }


  if (form.EMAIL.value == "")
  {
    alert("Please insert your e-mail address.");
    form.EMAIL.focus();
    return (false);
  }

  if (form.telephone.value == "")
  {
    alert("Please insert your telephone number.");
    form.telephone.focus();
    return (false);
  }
  
    if (form.arrival.value == "")
  {
    alert("Please insert the date of your arrival.");
    form.arrival.focus();
    return (false);
  }

  if (form.departure.value == "")
  {
    alert("Please insert the date of your departure.");
    form.departure.focus();
    return (false);
  }
  
    if (form.adults.value == "")
  {
    alert("Please insert the number of adults.");
    form.adults.focus();
    return (false);
  }


    if (!form.DataProtection.checked)
  {
    alert("Please read the data protection.");
    form.DataProtection.focus();
    return (false);
  }

}