function checkform (form)
{
	if (form.naam.value == "")
	{
		alert( "Vul uw NAAM in." );
		form.naam.focus();
		return false ;
	}
	else if (form.postcode.value == "")
	{
		alert( "Vul uw POSTCODE in." );
		form.postcode.focus();
		return false ;
	}
	else if (form.postcode2.value == "")
	{
		alert( "Vul ook de LETTERS van uw POSTCODE in." );
		form.postcode2.focus();
		return false ;
	}
	else if (form.postcode3.value == "")
	{
		alert( "Vul uw HUISNUMMER in." );
		form.postcode3.focus();
		return false ;
	}																
	else if (form.kengetal.value == "")
	{
		alert( "Vul uw TELEFOONNUMMER in." );
		form.kengetal.focus();
		return false ;
	}
	else if (form.telefoonnummer.value == "")
	{
		alert( "Vul uw COMPLETE TELEFOONNUMMER in." );
		form.telefoonnummer.focus();
		return false ;
	}
	else
	{
		return true ;
	}
}