function com_install()
{
    $parent = JInstaller::getInstance();
    $manifest = $parent->getManifest();
    $session = JFactory::getSession();
    $objJSNSubInstaller = new JSNSubInstaller();
    $ret = $objJSNSubInstaller->install();
    $errorArray = $objJSNSubInstaller->getError();
    $session->set('jsn_install_error', $errorArray);
    $resultCheckManifestFile = checkManifestFileExist();
    if ($resultCheckManifestFile == true) {
        beforeUpgradeImageShow();
        $objUpgradeDBUtil = new JSNISUpgradeDBUtil($manifest);
        $objUpgradeDBUtil->executeUpgradeDB();
    }
}
function com_uninstall()
{
    $objJSNSubInstaller = new JSNSubInstaller();
    $return = $objJSNSubInstaller->uninstall();
}