void ButtonAddTenseClick(object sender, EventArgs e)
 {
     if (listLang.SelectedIndex != -1)
     {
         string tenseName;
         if (EditValueDialog.ShowDialog(this, Strings.TenseNameHeader, Strings.TenseNameEnter, string.Empty, out tenseName))
         {
             KryptonListItem item     = (KryptonListItem)this.listLang.Items[this.listLang.SelectedIndex];
             Language        language = (Language)item.Tag;
             listTenses.Items.Add(language.AddTense(tenseName));
         }
     }
 }