validateForm.js

function validateForm() {
    var formIsValid = true;
    function enforceTextFieldMinLength(field, minLength) {
        if (!field.value || field.value.length < minLength) {
            formIsValid = false;
        }
    }
    function enforceLabelHasText(label) {
        if (!label.text) {
            formIsValid = false;
        }
    }
    // check first name
    enforceTextFieldMinLength(tfFirstName, 5);
    // check last name
    enforceTextFieldMinLength(tfLastName, 5);
    // check label connected to gender drop down
    enforceLabelHasText(lGender);
    if (formIsValid) {
        alert('Form is valid!');
    }
    else {
        alert('Form is invalid...');
    }
}