/// <summary>
/// when clicking on the 'Refresh' button, clear the table and reload it.
/// </summary>
private void RefreshClick(object sender, RoutedEventArgs e)
{
Refresh ob = fd.RefreshRates;
IAsyncResult asyncResult = ob.BeginInvoke(null, null);
ob.EndInvoke(asyncResult);
dictionary = fd.MyCurrencies;
currencies.DataContext = null;
currencies.DataContext = dictionary.Values;
PopulateComboBoxes();
}
