Fix for the conference pro theme to avoid issues with html select fields.

cfpro_fix.php

<?php
/*
Plugin Name: Conference Pro theme select input fix
Description: Restores standard web browser behavior for html selects on a specific page (in this case, the checkout page)
Author: Event Espresso support
Version: 1.0
*/

add_action('wp_enqueue_scripts', 'my_remove_conf_pro_conflict_script', 99);
function my_remove_conf_pro_conflict_script() {
    if (is_page('checkout')) {
        wp_deregister_script('cpt-select');
    }
}