public function deleteFile($fileName, $storageName = '')
    {
        //check whether file is set or not
        if ($fileName == '') {
            AsposeApp::getLogger()->error(Exception::MSG_NO_FILENAME);
            throw new Exception(Exception::MSG_NO_FILENAME);
        }

        //build URI
        $strURI = $this->strURIFile . $fileName;
        if ($storageName != '') {
            $strURI .= '?storage=' . $storageName;
        }
        //sign URI
        $signedURI = Utils::sign($strURI);

        $responseStream = json_decode(Utils::processCommand($signedURI, 'DELETE', '', ''));
        if ($responseStream->Code != 200) {
            return FALSE;
        }
        return TRUE;
    }