public function ColumnExists($ColumnName) {
      $Result = array_key_exists($ColumnName, $this->ExistingColumns());
      if (!$Result) {
         foreach ($this->ExistingColumns() as $ColName => $Def) {
            if (strcasecmp($ColumnName, $ColName) == 0)
               return TRUE;
         }
         return FALSE;
      }
      return $Result;
   }