func login_now(username:String, password:String)
{
    let post_data: NSDictionary = NSMutableDictionary()


    post_data.setValue(username, forKey: "username")
    post_data.setValue(password, forKey: "password")

    let url:URL = URL(string: login_url)!
    let session = URLSession.shared

    let request = NSMutableURLRequest(url: url)
    request.httpMethod = "POST"
    request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData

    var paramString = ""


    for (key, value) in post_data
    {
        paramString =  paramString + (key as! String) + "=" + (value as! String) + "&"

    }
    let endIndex = paramString.index(paramString.endIndex, offsetBy: -1)
    let truncated = paramString.substring(to: endIndex)
   paramString=truncated
    print(paramString)    // This won't consist of last &
    request.httpBody = paramString.data(using: String.Encoding.utf8)

    let task = session.dataTask(with: request as URLRequest, completionHandler: {
        (
        data, response, error) in

        guard let _:Data = data, let _:URLResponse = response  , error == nil else {

            return
        }



        let json: Any?

        do
        {
            json = try JSONSerialization.jsonObject(with: data!, options: [])

guard let server_response = json as? NSDictionary else
        {
            return
        }


        if let data_block = server_response["data"] as? NSDictionary
        {
            if let session_data = data_block["session"] as? String
            {
                self.login_session = session_data

                let preferences = UserDefaults.standard
                preferences.set(session_data, forKey: "session")

                DispatchQueue.main.async(execute: self.LoginDone)
            }
        }



    })

    task.resume()


}