Stop reputation being left without a comment

[simalert]

Hi,

On my forum I get people asking my support team quite often about who left them positive or negative reputation.

If the user leaving reputation puts a comment then vBulletin tells them who left it, if not then they can't see who left the reputation.

I would like to know if it's possible (and if not can someone make a hack please?) to make it so that you can only leave reputation (positive or negative) if you leave a comment with it.

Any ideas?

Thanks