// Dit script valideert velden en geeft error messages terug.
function checkFields()
{  
  if ( mail_form.naam.value   == "")
  { 
    alert( "Vul uw naam in s.v.p." );
    document.mail_form.naam.focus();
    return false;
  }
   
  if ( mail_form.straat.value =="")
  {
	alert( "Voer uw adres in s.v.p.");
	document.mail_form.adres.focus();
	return false;
  } 

  if ( mail_form.postcode.value =="")
  {
	alert( "Voer uw postcode in s.v.p.");
	document.mail_form.post.focus();
	return false;
  } 

  if ( mail_form.plaats.value =="")
  {
	alert( "Voer uw woonplaats in s.v.p.");
	document.mail_form.plaats.focus();
	return false;
  }

  if ( mail_form.telefoon.value == "" )
  {
	  alert("Geen juist telefoon nummer ingevoerd");
	  document.mail_form.telefoon.focus();
	  return false;
  }

  if ( mail_form.email.value || mail_form.email.value == "")
  {
	if ( mail_form.email.value.indexOf ('@', 0) == -1 || mail_form.email.value == "uw@mailadres.nl" ||
         mail_form.email.value.indexOf ('.', 0) == -1)
    {
      alert("'' " + mail_form.email.value + " '', is geen geldig email adres.");
	  document.mail_form.email.focus();
      return false;
	}
  }
}

function setfocus() 
{
  document.mail_form.naam.focus();
  return;
}