public static function dbCity($field, $data, $show, $blank = null, $attrs = null, $value = null, $label = '', $req = false, $err = false)
 {
     if (is_array($attrs)) {
         $attrs = Tag::getAttrs($attrs);
     }
     extract(parent::_getFieldData($field, $value === null), EXTR_OVERWRITE);
     if (is_null($blank)) {
         $options = '';
     } else {
         $options = '<option value="">' . htmlspecialchars($blank, ENT_COMPAT, APP_CHARSET) . '</option>';
     }
     foreach ($data as $p) {
         $options .= "<option value=\"{$p->id}\"";
         if ($p->id == $value) {
             $options .= ' selected="selected"';
         }
         $options .= '>' . $p->convencion . " | " . htmlspecialchars($p->{$show}, ENT_COMPAT, APP_CHARSET) . '</option>';
     }
     $attrs = self::_getAttrsClass($attrs, 'select', $req);
     $input = "\n<select id=\"{$id}\" name=\"{$name}\" {$attrs}>{$options}</select>\n";
     $input .= self::label($field, $label, null, $req, $err);
     return $input . "\n";
 }