function AlterColumnSQL($tabname, $flds, $tableflds='',$tableoptions='')
	{
		$tabname = $this->TableName ($tabname);
		$sql = array();
		list($lines,$pkey,$idxs) = $this->_GenFields($flds);
		// genfields can return FALSE at times
		if ($lines == null) $lines = array();
		$alter = 'ALTER TABLE ' . $tabname . $this->alterCol . ' ';
		foreach($lines as $v) {
			$sql[] = $alter . $v;
		}
		if (is_array($idxs)) {
			foreach($idxs as $idx => $idxdef) {
				$sql_idxs = $this->CreateIndexSql($idx, $tabname, $idxdef['cols'], $idxdef['opts']);
				$sql = array_merge($sql, $sql_idxs);
			}

		}
		return $sql;
	}