When adding context menus to large data structures like a 
            <table> or large list (<ol> 
            or <ul>), it is recommended to bind a single 
            YAHOO.widget.ContextMenu instance to the structure's root element, than to a set 
            of its child nodes (<tr>s or <li>s).
            
            Doing so significantly improves the performance of a web page or 
            application by reducing the number of "contextmenu" event handlers 
            as well as the number of YAHOO.widget.ContextMenu instances in memory.
        
This example demonstrates how to display a context menu when the user clicks on any of the labels of the nodes in a YAHOO.widget.TreeView instance.
Please Note: Opera users will need to do the following to use this example: