Inserting java script on the registration page

[Quads]

Hello,

I'm trying to insert a java script at the registration page, and the registration confirmation page.
Would one of you be so kind as to point me towards the template or file(s) I need to modify to do this?

I've found registration.php but am unable to find the registration completion page.
I'm assuming the best way to insert this is through the template manager?

The script is pretty basic:

<input type="hidden" name="OI_FORM_IDENTIFIER" value=""/>
<SCRIPT LANGUAGE="JavaScript" SRC="http://www.blahblahblah.js"></SCRIPT>

I need to insert one in the registration page, and the another in the registration confirmation page where it tells users to verify their email, etc.

Any help would be much appreciated. I've searched the forum, the manual, the docs, google, etc.