Use the UnselectAll method to unselect all items in the
list. The UnselectAll method has effect only if the SingleSel
property is False, if the control supports multiple items selection. Use the SelectAll
method to select all items in the list. Use the SelectItem
property to select or unselect a specified item. Use the SelectedItem
property to retrieve a value that indicates whether the item is selected or
unselected. Use the SelectCount property
to retrieve the number of selected items. The RemoveSelection
method removes the selected items (including the descendents)