9999';
                   option.disabled = true;
                   if (option.selected)
                     obj.options[len-1].selected = true;
                 }
                 else {
                   option.style.color = '';
                   option.disabled = false;
                 }
               }
               break;
             default:
               for (i=0; i<len; i++) {
                 option = obj.options[i];
                 option.style.color = '';
                 option.disable