[thelist] javascript: ensuring that at least one radio button is selected

[Joel D Canfield]

I have two dozen radio buttons, named 'PrimaryIssue', all with different
IDs/values. In this case, a default choice doesn't make sense. How do I
ensure that at least one choice has been made?

I've tried checking the value of 'PrimaryIssue', but that dinna work. I
hate listing each ID separately. Is 'PrimaryIssue' an array I have to
loop through?

thanks

joel