if (!$dbKITcontact->sqlFieldExists(dbKITcontact::field_distribution)) {
    if (!$dbKITcontact->sqlAlterTableAddField(dbKITcontact::field_distribution, "VARCHAR(255) NOT NULL DEFAULT ''", dbKITcontact::field_newsletter)) {
        $error .= sprintf('<p>[Upgrade] %s </p>', $dbKITcontact->getError());
    }
}
// install tables for newsletter module
$dbKITnewsletterTemplates = new dbKITnewsletterTemplates();
if (!$dbKITnewsletterTemplates->sqlTableExists()) {
    if (!$dbKITnewsletterTemplates->sqlCreateTable()) {
        $error .= sprintf('<p>[Upgrade] %s</p>', $dbKITnewsletterTemplates->getError());
    }
}
$dbKITnewsletterPreview = new dbKITnewsletterPreview();
if (!$dbKITnewsletterPreview->sqlTableExists()) {
    if (!$dbKITnewsletterPreview->sqlCreateTable()) {
        $error .= sprintf('<p>[Upgrade] %s</p>', $dbKITnewsletterPreview->getError());
    }
}
$dbKITnewsletterCfg = new dbKITnewsletterCfg();
if (!$dbKITnewsletterCfg->sqlTableExists()) {
    if (!$dbKITnewsletterCfg->sqlCreateTable()) {
        $error .= sprintf('<p>[Upgrade] %s</p>', $dbKITnewsletterCfg->getError());
    }
}
$dbKITnewsletterArchive = new dbKITnewsletterArchive();
if (!$dbKITnewsletterArchive->sqlTableExists()) {
    if (!$dbKITnewsletterArchive->sqlCreateTable()) {
        $error .= sprintf('<p>[Upgrade] %s</p>', $dbKITnewsletterArchive->getError());
    }
}
// check support for distributions --> #0.29
$dbKITmail = new dbKITmail(true);
if ($dbKITmail->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITmail->getError());
}
$dbKITregister = new dbKITregister(true);
if ($dbKITregister->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITregister->getError());
}
// Install tables for newsletter module
$dbKITnewsletterTemplates = new dbKITnewsletterTemplates(true);
if ($dbKITnewsletterTemplates->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITnewsletterTemplates->getError());
}
$dbKITnewsletterPreview = new dbKITnewsletterPreview(true);
if ($dbKITnewsletterPreview->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITnewsletterPreview->getError());
}
$dbKITnewsletterCfg = new dbKITnewsletterCfg(true);
if ($dbKITnewsletterCfg->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITnewsletterCfg->getError());
}
$dbKITnewsletterArchive = new dbKITnewsletterArchive(true);
if ($dbKITnewsletterArchive->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITnewsletterArchive->getError());
}
$dbKITnewsletterProcess = new dbKITnewsletterProcess(true);
if ($dbKITnewsletterProcess->isError()) {
    $error .= sprintf('<p>[Installation] %s</p>', $dbKITnewsletterProcess->getError());
}
$dbCronjobData = new dbCronjobData(true);
if ($dbCronjobData->isError()) {
$dbKITregister = new dbKITregister();
if ($dbKITregister->sqlTableExists()) {
    if (!$dbKITregister->sqlDeleteTable()) {
        $error .= sprintf('<p>[Delete Table] %s </p>', $dbKITregister->getError());
    }
}
$dbKITnewsletterCfg = new dbKITnewsletterCfg();
if ($dbKITnewsletterCfg->sqlTableExists()) {
    if (!$dbKITnewsletterCfg->sqlDeleteTable()) {
        $error .= sprintf('<p>[Delete Table] %s</p>', $dbKITnewsletterCfg->getError());
    }
}
$dbKITnewsletterPreview = new dbKITnewsletterPreview();
if ($dbKITnewsletterPreview->sqlTableExists()) {
    if (!$dbKITnewsletterPreview->sqlDeleteTable()) {
        $error .= sprintf('<p>[Delete Table] %s</p>', $dbKITnewsletterPreview->getError());
    }
}
$dbKITnewsletterTemplates = new dbKITnewsletterTemplates();
if ($dbKITnewsletterTemplates->sqlTableExists()) {
    if (!$dbKITnewsletterTemplates->sqlDeleteTable()) {
        $error .= sprintf('<p>[Delete Table] %s</p>', $dbKITnewsletterTemplates->getError());
    }
}
$dbKITnewsletterArchive = new dbKITnewsletterArchive();
if ($dbKITnewsletterArchive->sqlTableExists()) {
    if (!$dbKITnewsletterArchive->sqlDeleteTable()) {
        $error .= sprintf('<p>[Delete Table] %s</p>', $dbKITnewsletterArchive->getError());
    }
}
$dbKITnewsletterProcess = new dbKITnewsletterProcess();