How to use a JavaScript variable in an XSL template?

Hello, this is my first post and I am somewhat new to XSL. I am trying to do
the following:

1) Use XSL to parse an XML file and build an HTML table of data retrieved from
the XML file.
2) I am using an HTML5 localStorage variable to determine which "type" of user
the user selects from a previous combo box. Once selected in the combo box,
this variable is written out with JavaScript.
3) My XSL template will check this variable and parse the XML according to
what "type" of user is selected.

Here is the XLS headers I am using:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:set="http://exslt.org/sets" exclude-result-prefixes="set">

And here is my dream code:

<xsl:for-each select="user[@type='JAVASCRIPT_VARIABLE']">

I can't get the syntax for the above line of code to work. I have the
JavaScript working alone. I have the XSL working when I hardcode
JAVASCRIPT_VARIABLE to be equal to the userType that is stored. But I can't
get the XSL syntax right to allow me to swap in a JavaScript variable into a
line of XSL code.

This works fine:
<xsl:for-each select="user[@type='novice']">

Basically, I need to replace "novice" with whatever the JavaScript function
returns. It could be novice, advanced, or expert.

Any ideas? Thank you in advance for your help. I couldn't find anything in the
archives that worked. Trust me, I am on day three of trying to fix a single
line of code. :)

Ryan
Cambridge, MA