RadTreeView introduces several server-side events for working with nodes:
    
    
        - NodeClick occurs when the user clicks one of the tree nodes
- NodeDrop occurs when a node is dragged and dropped
- NodeCheck  occurs when the user checks or un-checks a node
            checkbox
- NodeDataBound occurs when a node is bound to data
- NodeEdit occurs when the user clicks twice on the node or presses
            F2 to cause a node to be edited
- NodeExpand occurs when node is expanded to display child nodes
- NodeCollapse occurs when a node is collapsed to hide child nodes
- NodeCreated occurs when a node is first created
- ContextMenuItemClick occurs when a context menu item is clicked
        This example shows how the NodeClick, NodeExpand 
        and NodeCollapse events can be wired up.
    
    
        As soon as the NodeClick event is wired, a postback will appear.
        You can disable the postback for a node by setting its PostBack
        property to false.
    
        Please review the source code of this example for additional details.
    
 
    
        - Click a tree node to trigger the NodeClick event
- Expand a tree node to trigger the NodeExpand event
- Collapse a tree node to trigger the NodeCollapse event