Populate Smarty variable from jQuery plugin

[MrBaseball34]

I'm rewriting the GoogleBase module and adding loads of features.
I am using a jQuery plugin called OptionTree and need to take the value
that the user selected and store it in a Smarty variable.

How would I do that? I don't see any examples of that in PS at all.

Here's a demo of the usage of the OptionTree:
http://www.partreports.com/treetest.php

jquery.optionTree.js is where the change() function is when the user selects an item and that is where I need to populate the smarty variable, somehow...

[MrBaseball34]

This has been updated to correctly identify the jQuery plugin being used and the module that is being modified.