function RenameColumnSQL($tabname,$oldcolumn,$newcolumn,$flds='')
	{
		$tabname = $this->TableName ($tabname);
		if ($flds) {
			list($lines,$pkey,$idxs) = $this->_GenFields($flds);
			// genfields can return FALSE at times
			if ($lines == null) $lines = array();
			$first  = current($lines);
			list(,$column_def) = preg_split("/[\t ]+/",$first,2);
		}
		return array(sprintf($this->renameColumn,$tabname,$this->NameQuote($oldcolumn),$this->NameQuote($newcolumn),$column_def));
	}