function processTransformation($xml, $xsl)
{
    global $def;
    $result = "";
    $xslParams = array('xml-path' => $def['DATABASE_PATH'] . "xml/");
    $transform = new XSLTransformer();
    if ($def["LETTER_UNIT"] != "") {
        $transform->setXslBaseUri("file://" . $def["LETTER_UNIT"] . "/" . $def["SITE_PATH"]);
    } else {
        $transform->setXslBaseUri("file://" . $def["SITE_PATH"]);
    }
    if ($transform->setXml($xml) == false) {
        die($transform->getErrorMessage());
    }
    if ($transform->setXsl($xsl) == false) {
        die($transform->getErrorMessage());
    }
    $transform->setXslParameters($xslParams);
    if ($transform->transform() == false) {
        print $transform->getErrorMessage();
    } else {
        $result = utf8_decode($transform->getOutput());
    }
    return $result;
}