incorrectly checks the response c#

Question

I have a code that gets a response from the POST request:

//Запрос авторизации бухаря
        WebRequest request = WebRequest.Create("http://clannr.org/scripts/login/auth.php");
        request.Method = "POST";
        string postData = "user=" + Login.Text + "&password=" + Password.Text + "&version=13";
        byte[] byteArray = Encoding.UTF8.GetBytes(postData);
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = byteArray.Length;
        Stream dataStream = request.GetRequestStream();
        dataStream.Write(byteArray, 0, byteArray.Length);
        dataStream.Close();
        WebResponse response = request.GetResponse();
        Console.WriteLine(((HttpWebResponse)response).StatusDescription);
        dataStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(dataStream);
        string responseFromServer = reader.ReadToEnd();
        reader.Close();
        dataStream.Close();
        response.Close();

But when checking the response:

        Match match = regex.Match(responseFromServer);

if (match.Success)
        {
            var input = responseFromServer;
            var split = input.Split(':');
            var final = split[3];
            ProcessStartInfo mcStartInfo = new ProcessStartInfo("javaw", "-Xms1024m -Xmx1024m -cp \"" + appData + "\\.ClanNR\\bin\\minecraft1.jar;" + appData + "\\.ClanNR\\bin\\jinput.jar;" + appData + "\\.ClanNR\\bin\\lwjgl.jar;" + appData + "\\.ClanNR\\bin\\lwjgl_util.jar \" -Djava.library.path=\"" + appData + "\\.ClanNR\\bin\\natives\" net.minecraft.client.Minecraft" + " " + username + " " + final + " " + server1);
            Process.Start(mcStartInfo);
            this.Close();



        }

        else if (responseFromServer == " Bad Login")
        {
            MessageBox.Show("Uncorrect login/password!");
        }
        else if (responseFromServer == " Old version")
        {
            MessageBox.Show("Launcher is old!");
        }

My code called just 2 functions, i.e. show 2 MessageBox

How to fix it?

UPDATED

Answer 1

Firstly, the != operator means not-equal.
Correct me if i'm wrong, but I think you wanted to use ==.

if (responseFromServer == " Bad Login")
{
    MessageBox.Show("Uncorrect login/password!");
}

else if (responseFromServer == " Old version")
{
    MessageBox.Show("Launcher is old!");
}

Secondly, you should use else if. if the first condition is true, then it won't check the other.

Answer 2

Because if, say, responseFromServer variable equals to "Foo" then it fits both conditions, because it's not equal to " Bad Login" and not equal to " Old version"

What you probably want is else if:

    if (responseFromServer != " Bad Login")
    {
        MessageBox.Show("Uncorrect login/password!");
    }
    else if (responseFromServer != " Old version")
    {
        MessageBox.Show("Launcher is old!");
    }

Or probably you wanted == instead of !=

if (responseFromServer == " Bad Login")

So it's your job now to find out what you really want to achieve.

PS: are spaces in the beginning of both strings intended?