function checkform(form)
{
  // see http://www.thesitewizard.com/archive/validation.shtml
  // for an explanation of this script and how to use it on your
  // own website

  // ** START **
	
	var message = ""
	if(form.name.value == "") 
	{
		message = message +"- No name\n"
		form.name.focus();
	}

	if(form.email.value == "") 
	{
		message = message +"- No emailadres\n"
		form.email.focus();
	}

	if(form.address_1.value == "") 
	{
		message = message +"- No address\n"
		form.address_1.focus();
	}

	if(form.postalcode.value == "") 
	{
		message = message +"- No zipcode\n"
		form.postalcode.focus();
	}

	if(form.city.value == "") 
	{
		message = message +"- No city\n"
		form.city.focus();
	}
	
	if(message != "")
	{
		message = "You haven't filled in all the fields:\n"+ message
		alert(message);
		return false ;
	}
// ** END **
	return true ;
}