HTTP 505 Error

I am trying to make a GET request to the below listed url which should return an XML. When I put the compete url in my browser, I get the intended XML.

http://axml.travelnow.com/external/xmlinterface.jsp?cid=1&resType=air&intfc=ws&xml=&lt;AirSessionRequest method="getAirAvailability"><AirAvailabilityQuery><originCityCode>MCI</

<destinationCityCode>ATL</ <departureDateTime>11/19/2005 11:00 AM</ <returnDateTime>11/21/2005 10:00 AM</ <fareClass>Y</fareClass><tripType>R</ <Passengers> <adultPassengers>1</adultPassengers></ </AirAvailabilityQuery></AirSessionRequest>

However, when I try to make a request with Net:HTTP I get a HTTPNotValidError.

Here is what I have:

url = URI.parse('http://axml.travelnow.com') req = Net::HTTP::Get.new("/external/xmlinterface.jsp? cid=1&resType=air&intfc=ws&xml=<AirSessionRequest method="getAirAvailability"><AirAvailabilityQuery><originCityCode>MCI</

<destinationCityCode>ATL</ <departureDateTime>11/19/2005 11:00 AM</ <returnDateTime>11/21/2005 10:00 AM</ <fareClass>Y</fareClass><tripType>R</ <Passengers> <adultPassengers>1</adultPassengers></ </AirAvailabilityQuery></AirSessionRequest")

    res = Net::HTTP.start(url.host, url.port) {|http|       http.request(req)     } puts res puts res.body

There error I get is:

HTTPVersionNotSupported # 505