/**
 * Script by traininghaus: [info@traininghaus.ie]
 * Last Updated: Jan 2007
 */

function validateForm(f) {
	if (f.Firstname.value == "") {
		alert("Please enter your first name");
		f.Firstname.focus();
		return false;
	} else if (f.Lastname.value == "") {
		alert("Please enter your last name");
		f.Lastname.focus();
		return false;
	} else if (!isValidPhoneNumber(f.Phone.value) && !isValidEmail(f.Email.value)) {
		alert("Please enter either a Phone Number or an Email Address");
		f.Phone.focus();
		return false;
	} else {
		return true;
	}
	
}

// very basic format checker
function isValidEmail(email) {
	var indexOfAt = email.indexOf("@");
	if (indexOfAt == -1) {
		return false;
	}

	// split off domain part
	var domain = email.substring(indexOfAt+1, email.length);
	var indexOfDot = domain.indexOf(".");
	if (indexOfDot < 1) {
		return false;
	}
	if (indexOfDot > domain.length-3) {
		return false;
	}

	return true;
}

// very basic phone number format checker
function isValidPhoneNumber(phone) {
	// too short?
	if (!phone || phone.length < 7) {
		return false;
	}

	// any letters?
	var textPattern = /[a-zA-Z]/;
	if (textPattern.test(phone)) {
		return false;
	}

	return true;
}