function my_custom_checkout_field_process()
{
    global $woocommerce;
    if (!$_POST['net_id']) {
        wc_add_notice('<strong>NetID</strong> is required.', $notice_type = 'error');
    } else {
        if (!$_POST['uofrpassword']) {
            wc_add_notice('<strong>Password</strong> is required.', $notice_type = 'error');
        } else {
            if (validatecredentials($_POST['net_id'], $_POST['uofrpassword']) == false) {
                //if netid and password are not valid
                wc_add_notice('<strong>The NetID or password you entered is incorrect. Please try again.</strong>', $notice_type = 'error');
            }
        }
    }
}
         $username = $_GET['username'];
         $password = $_GET['password'];
         break;
     case 'PUT':
         break;
     case 'POST':
         $username = $_POST['username'];
         $password = $_POST['password'];
         break;
     case 'DELETE':
         break;
 }
 if (empty($username) || empty($password)) {
     sendresponse($response, 3, false, $api_response_code);
 }
 $user_id = validatecredentials($username, $password);
 if ($user_id == false) {
     sendresponse($response, 4, false, $api_response_code);
 } else {
     switch ($method) {
         case 'GET':
             $sql_select = "SELECT categories.* FROM categories";
             $entries = get_categories($sql_select);
             if ($entries == false) {
                 sendresponse($response, 5, false, $api_response_code);
             } else {
                 $response['data'] = $entries;
             }
             break;
         case 'PUT':
             die("update table");