How to add an event listener for change on a checkbox within oj-checkboxset

Summary:

How do we add an event listener (probably a "change" event) so that when one checkbox in a checkbox set is selected, another is automatically selected within the same checkbox set.

I should really be asking how can I include my own JavaScript on the page for checkbox's or other elements? - My efforts so far in attempting to add an extremely simple 'change' event listener within the JavaScript section returns parsing errors.

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VBCS Redwood

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