protected function checkBrowserNetscape()
    {
        //BlackBerry & Nokia UAs can conflict with Netscape UAs
        if ($this->containString($this->_agent, array('BlackBerry', 'Nokia'), true, false)) {
            return false;
        }

        //Netscape v6 to v9 check
        if ($this->checkSimpleBrowserUA(array('Netscape', 'Navigator', 'Netscape6'), $this->_agent, self::BROWSER_NETSCAPE)) {
            return true;
        }

        //Netscape v1-4 (v5 don't exists)
        $found = false;
        if ($this->containString($this->_agent, 'Mozilla') && !$this->containString($this->_agent, 'rv:', true, false)) {
            $version = '';
            $verParts = explode('/', stristr($this->_agent, 'Mozilla'));
            if (count($verParts) > 1) {
                $verParts = explode(' ', $verParts[1]);
                $verParts = explode('.', $verParts[0]);

                $majorVer = $this->parseInt($verParts[0]);
                if ($majorVer > 0 && $majorVer < 5) {
                    $version = implode('.', $verParts);
                    $found = true;

                    if (strtolower(substr($version, -4)) == '-sgi') {
                        $version = substr($version, 0, -4);
                    } else {
                        if (strtolower(substr($version, -4)) == 'gold') {
                            $version = substr($version, 0, -4) . ' Gold'; //Doubles spaces (if any) will be normalized by setVersion()
                        }
                    }
                }
            }
        }

        if ($found) {
            $this->setBrowser(self::BROWSER_NETSCAPE);
            $this->setVersion($version);
            $this->setMobile(false);
            $this->setRobot(false);
        }

        return $found;
    }