// check if running on IIS < 6 with CGI-PHP
if ((isset($_SERVER['SERVER_SOFTWARE'])) && (isset($_SERVER['GATEWAY_INTERFACE'])) &&
- (strpos($_SERVER['GATEWAY_INTERFACE'], 'CGI') !== false) &&
+ (isInString('CGI', $_SERVER['GATEWAY_INTERFACE'])) &&
(preg_match('|^Microsoft-IIS/(\d)\.\d$|', trim($_SERVER['SERVER_SOFTWARE']), $matches)) &&
($matches[1] < 6)) {
// Send the IIS header