C# Serialize and send over Network

Hi,
I want to serialize a class and send it over tcp. Thats no problem, but I get an exception while deserializing the stream in the client application.
Thats my code:

[Serializable]
internal class SendObj1
{

    public int cmd;
    public string msg;
}

public class SendObj
{
    public int cmd;
    public string msg;
    public byte[] ToByte(int Command)
    {
        SendObj1 obj1 = new SendObj1();
        obj1.cmd = Command;
        XmlSerializer xs = new XmlSerializer(typeof(SendObj1));
        MemoryStream ms = new MemoryStream();
        xs.Serialize(ms, obj1);
        return ms.ToArray();
    }
    public byte[] ToByte(int Command, string Message)
    {
        SendObj1 obj1 = new SendObj1();
        obj1.cmd = Command;
        obj1.msg = Message;
        XmlSerializer xs = new XmlSerializer(typeof(SendObj1));
        MemoryStream ms = new MemoryStream();
        xs.Serialize(ms, obj1);
        return ms.ToArray();
    }
    public SendObj ToObj(byte[] buffer)
    {
        SendObj1 obj = new SendObj1();
        try
        {
            XmlSerializer xs = new XmlSerializer(typeof(SendObj1));
            MemoryStream ms = new MemoryStream();
            obj = (SendObj1) xs.Deserialize(ms);
            msg = obj.msg;
            cmd = obj.cmd;
        }
        catch (Exception e)
        {
        }
        return this;
    }

Tags: C#, Network, Serialization