private void GetServicesButton_Click(object sender, System.Windows.RoutedEventArgs e)
{
_serverUri = new Uri(MySvrTextBox.Text);
// Add the parameter f=json to return a response in json format
IDictionary<string, string> parameters = new Dictionary<string, string>();
parameters.Add("f", "json");
// If another request is in progress, cancel it
if (_webclient.IsBusy)
_webclient.CancelAsync();
_webclient.OpenReadAsync(_serverUri, parameters);
}