if ((basename($_SERVER['PHP_SELF']) == "install.php") || (!isBooleanConstantAndTrue('mxchange_installed')) || (isset($_GET['installing']))) $STYLES[] = "install.css";
// When no CSS output-mode is set, set it to file-output
-if (getConfig('css_php') == null) setConfigEntry('css_php', "FILE");
+if (!isConfigEntrySet('css_php')) setConfigEntry('css_php', "FILE");
// Output CSS files or content or link to css.php ?
if (($CSS == "1") || (getConfig('css_php') == "DIRECT")) {