function isFilled(elm) {
	if (elm.value == "" || elm.value == null)
		return false;
	return true;
}

function isEmail(elm) {
	if (elm.value.indexOf("@") + "" != "-1" &&
		elm.value.indexOf(".") + "" != "-1" &&
		elm.value != "")
		return true;
	return false;
}

function isRegister(form) {

	if (isFilled(form.member_number) == false) {
		alert("Please fill in your membership number.");
		form.member_number.focus();
		return false;
	}

	if (isFilled(form.forename) == false) {
		alert("Please fill in your first name.");
		form.forename.focus();
		return false;
	}

	if (isFilled(form.surname) == false) {
		alert("Please fill in your last name.");
		form.surname.focus();
		return false;
	}

	if (isEmail(form.email) == false) {
		alert("Please insert a correct email address.");
		form.email.focus();
		return false;
	}

	if (isFilled(form.password1) == false) {
		alert("Please enter a password.");
		form.password1.focus();
		return false;
	}

	if (isFilled(form.password2) == false) {
		alert("Please enter your password a second time.");
		form.password2.focus();
		return false;
	}

	if (form.password1.value != form.password2.value) {
		alert("The passwords you have entered do not match.");
		form.password1.focus();
		return false;
	}

	if (isFilled(form.tel_number) == false) {
		alert("Please fill in your telephone number.");
		form.tel_number.focus();
		return false;
	}

	if (isFilled(form.address) == false) {
		alert("Please fill in your address.");
		form.address.focus();
		return false;
	}

	return true;
}