XML-Binded TreeView - How to select node on client side without PostBack

[amirmi]

Hi,
I Have a Treeview that represent Stock Indicators.
The idea is when i press the indicator i want it to create a
client-side table with all the parameters of this indicator - which are
listed in the XML under "IndicatorParam"

The problem is that i DONT WANT TO USE POSTBACK.
I, of course Changed the "SelectAction" for this node to "none" instead
of "select" to disable the post-back.
but what now? i want to use javascript for building the table, but for
that i need to know the "Selected Node" without going to the
server-side and fetch it. (hence post-back)
I also need to access the XML and retrieve the parameters for this
SelectedNode

anyone has any idea how to to it? is it a lost battle and i have to do
a postback?

XML Stracture:

<IndicatorsGroups>
<Group>
<Indicator>
<IndicatorParam>