// Script de chequeo de formulario
function check_fields(f) {
	form = document.forms[f];

	if ( !form.name.value) {
		alert("Please enter your name so that your friend knows who's writing.");
		form.name.focus();
		return false;
	}
	else if ( !form.email.value) {
		alert("Please enter your email in order that your friend can reply to you.");
		form.email.focus();
		return false;
	}
	else if ( !form.friend.value) {
		alert("If you don't type your friend's mail, we cannot contact him/her! \n\nPlease try again.");
		form.friend.focus();
		return false;
	}
	else {
		return true;
	}

}