function custom_form_generate($atts)
{
    global $wpdb;
    //allows us to have database tables access
    extract(shortcode_atts(array('invoice_name' => 'stuff', 'invoice_type_id' => 'stuff'), $atts, 'cfg'));
    set_external_js_css($invoice_type_id);
    // add linked js and css files
    /* Form Validation/Submission Handler */
    if ($_POST) {
        if ($invoice_type_id != 17) {
            $error_messages = custom_form_generate_validation($invoice_type_id);
            $form .= $error_messages;
            //output error messages
        }
        if (!$error_messages) {
            $form .= handle_submission($invoice_type_id);
        }
    }
    // if $_POST
    if (!$_POST || $_POST && $error_messages) {
        $form .= display_form($invoice_type_id);
    }
    return $form;
}
/**
 * Displays the content for the FAQs tab
 * the form and the faq loop
 *
 * @since    3.0.0
 */
function faq_tab_content()
{
    //handle the submission if it posted
    if (isset($_POST['submit_faq']) && $_POST['submit_faq']) {
        $result = handle_submission();
    }
    //the faqs loop
    include __DIR__ . '/templates/loop-faqs.php';
    $disable_ask = get_option(WOOFAQS_OPTIONS_PREFIX . '_disable_ask', false);
    if (!$disable_ask || $disable_ask === 'no') {
        //the faq form
        include __DIR__ . '/templates/faq-form.php';
    }
}