private function mkdir_p( $dir )
    {
        // create parent directories
        $dirElements = explode( '/', $dir );
        if ( count( $dirElements ) == 0 )
            return true;

        $result = true;
        $currentDir = $dirElements[0];

        if ( $currentDir != '' && !file_exists( $currentDir ) && !eZDir::mkdir( $currentDir, false ) )
            return false;

        for ( $i = 1; $i < count( $dirElements ); ++$i )
        {
            $dirElement = $dirElements[$i];
            if ( strlen( $dirElement ) == 0 )
                continue;

            $currentDir .= '/' . $dirElement;

            if ( !file_exists( $currentDir ) && !eZDir::mkdir( $currentDir, false ) )
                return false;

            $result = true;
        }

        return $result;
    }