tree similar to example 2. the special things here are:
there is an onClickCaption event on all tree elements.
it fires an assigned alert function.
the tree element will remain active (clicked), see the yellow background. this is a customizable default behavior.
the 'yahoo sports' node has an 'onBeforeOpen' and 'onBeforeClose' event attached. it checks if it's allowed to toggle the node.
allow toggling "yahoo sports" node