min = document.getElementById(prefix + 'promo_min').value;
max = document.getElementById(prefix + 'promo_max').value;
if (isNaN(min) || (min != 0 && (min < 1900 || min > 2020))) {
min = document.getElementById(prefix + 'promo_min').value;
max = document.getElementById(prefix + 'promo_max').value;
if (isNaN(min) || (min != 0 && (min < 1900 || min > 2020))) {