Template OR statement to determine which script to use

I have two different off-page linked rollover javascripts. One is for the primary navigation level, the second for the sub-nav level. I am setting up templates and want to call one or the other depending upon a boolean parameter called "script_id". If "script_id" is "true" then the page will call script 1. If "script_id" is "false" then it will call script 2.

Here is the code i am using in the head of the document.

<!-- TemplateBeginMultipleIf -->
<!-- TemplateBeginIfClause cond="script_id == 'false'" -->
<script src="../aus-sub-script.js"></script>
<!-- TemplateEndIfClause -->
<!-- TemplateBeginIfClause cond="script_id == 'true'" -->
<script src="../aus-sub-sub-script.js"></script>
<!-- TemplateEndIfClause -->
<!-- TemplateEndMultipleIf -->

However, it is not working. For some reason, the subpage is not calling either script, and the rollovers are not working.

Does anyone have any ideas on this?

Thanks mucho,

Glenn