fatal error: unexpectedly found nil while unwrapping an Optional value

I have a problem when I compile my code. I don't understand what is this problem. Could you help me please ? :) My error is: fatal error: unexpectedly found nil while unwrapping an Optional value

Thanks !!

var bodyData = "tel_client=\(phoneNumber)&id_pays=\(phoneCode)&datetime_alibi=\(getDateTimeFormat(date))&tel_contact=\(to)&nb_rappel_alibi=1&pr_rappel_alibi=5"
//println(bodyData)
request.HTTPBody = bodyData.dataUsingEncoding(NSUTF8StringEncoding)
NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue()) {
    (response, data, error) in
    var error: NSError?
    var jsonData: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options:nil, error: &error) as NSDictionary

    if jsonData["success"] as Int == 1 {
        let alertView = UIAlertView(title: "GOOD", message: nil, delegate: self, cancelButtonTitle: "ok")
        alertView.show()
    } else {
        let alertView = UIAlertView(title: "ERROR", message: jsonData["message"] as? String, delegate: self, cancelButtonTitle: "ok")
        alertView.show()
    }
}