Invalid cross thread access

private  void GetResponseCallback(IAsyncResult asynchronousResult)
{
    HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
    HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
    Stream streamResponse = response.GetResponseStream();
    StreamReader streamRead = new StreamReader(streamResponse);
    string responseString = streamRead.ReadToEnd();
    MemoryStream ResMs = new MemoryStream(Encoding.UTF8.GetBytes(responseString));
    DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(Pos_Silverlight.DataContract.Response));
    Pos_Silverlight.DataContract.Response _ResLogIn = (Pos_Silverlight.DataContract.Response)ser.ReadObject(ResMs);
    if (_ResLogIn.Code == "1")
    {
        //I am getting Error Hear Only
        Home obj = new Home();
        this.Content = obj;
    }
    else
    {
        MessageBox.Show("InValied UserName and PassWord");
        return;
    }
    streamResponse.Close();
    streamRead.Close();
    response.Close();
}