public function replaceBlock($blockname, $replacement)
    {
        preg_match( '/\$\{' . $blockname . '}.*\$\{\/' . $blockname . '}/is', 
        $this->tempDocumentMainPart, $matches ); 
        
        if (isset($matches[0])) { $this->tempDocumentMainPart = str_replace( $matches[0], $replacement, 
            $this->tempDocumentMainPart );}

    }