private void ClearButton_Click(object sender, RoutedEventArgs e)
        {
            Button      cb        = sender as Button;
            string      fieldName = cb.Name.Substring(0, cb.Name.Length - 4);
            BackupImage img       = register[fieldName + UI_ELEMENT_SUFFIX] as BackupImage;

            img.SetSourceAndBackup(null);
            Label lab = register[fieldName + "_lab"] as Label;

            lab.Content = "<No file>";
        }
        private void BrowseButton_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            Button         bb  = sender as Button;

            ofd.DefaultExt = ".png";
            ofd.Filter     = "Image Files|*.jpeg;*.png;*.jpg;*.gif|JPEG Files (*.jpeg)|*.jpeg|PNG Files (*.png)|*.png|JPG Files (*.jpg)|*.jpg|GIF Files (*.gif)|*.gif";
            if (ofd.ShowDialog() == true)
            {
                XImage      xi        = new XImage(ofd.FileName, false);
                string      fieldName = bb.Name.Substring(0, bb.Name.Length - 3);
                BackupImage img       = register[fieldName + UI_ELEMENT_SUFFIX] as BackupImage;
                img.SetSourceAndBackup(xi);
                Label lab = register[fieldName + "_lab"] as Label;
                lab.Content = ofd.FileName.Substring(ofd.FileName.LastIndexOf('\\'));
            }
        }