Forum:Template with opening tag only

Hello template gurus! :)

How do I create a template that contains an unclosed opening tag and a corresponding template with an unopened closing tag?

A little background: I'd like to add a little formatting to my JavaScript code but want it to be as unobtrusive as possible. For starters - and really: this is just the beginning - I'd like to create a template (or two) for the opening and closing source-tag. The template is supposed to be used like this:

What I've tried so far is this (and quite a few variations of it):

But it's not working. Either I get "| End =" rendered as JavaScript or the tag is inserted but not rendered.

Is there anything I can do to fix this? --