drop confirmation for registration

One request our A&R departments have had for a long time is a warning to students when they're about to drop classes in SSB registration page. It usually gets blamed on scroll-wheel mice -- if you scroll when over the "Action" list for a CRN, you might change it to "Drop" from "None" accidentally.

I put together some javascript code to prompt the user to find out if they really want to drop/withdraw. We haven't gone into production with it yet, but it works for me with IE, Firefox and Opera, so I think it's ready.

You can find the code attached.

Where do you put it? I put it into a DEFAULT info text entry for bwskfreg.P_AddDropCrse. It overrides the checkSubmit function that appears earlier in the page source code. No mods necessary!