function validate(f) {
	if (f.consultation_message.value == "") {
		alert("Please, indicate a subject of appointment.");
		f.consultation_message.focus();
		return false;
	}
	if (f.consultation_email.value == "" && f.consultation_phone.value == "") {
		alert("Please, indicate your email or telephone.");
		f.consultation_email.focus();
		return false;
	}
}