function isValidData(form) {
	// check account number length
	if (form.accountNumber.value.length < 8) {
		alert('Please enter a valid Account number.');
		return false;
	}
	// check account number is a number
	if (isNaN(parseInt(form.accountNumber.value))) {
		alert('Please enter a valid Account number.');
		return false;
	}
	return true;
}