private void buttonAddCollection_Click(object sender, EventArgs e)
{
MarkCollection newCollection = new MarkCollection();
newCollection.Name = "New Collection";
MarkCollections.Add(newCollection);
// populate the form with the new collection first, *then* update the collection list,
// so that the displayed collection is remembered and selected in the list.
PopulateFormWithMarkCollection(newCollection);
PopulateMarkCollectionsList();
}