Re: "Tooltip" pop-up identifiers

Sixth attempt at posting this: Google seems to be having a bit of
trouble.

Thanks for the example (doesn't work in IE, by the way).

My application has to identify polygons from a user-specified point on
the map. I can't give a link because the polygon data isn't entirely
public-domain and I haven't got permission to publish it yet, but I'm
doing some development in expectation of being able to publish.

I'm actually dealing with Church of England parishes. Parishes can vary
in size from a few streets to comparatively large tracts of open
country, but it's important to be able to identify the boundaries -- as
being on the "wrong" side can affect where weddings can take place (for
example). I have boundary data digitised to an accuracy of 1 metre.
Boundaries often run down the middle of streets, and in a few cases
through the middle of buildings. Parishes can also have holes in them,
and/or "detached" areas which are isolated islands -- sometimes quite a
few miles away from the main bit.

Because of the disparity in polygon area, it's not really feasible to
use a single point to help identify the area: at the level of zoom
required, the marker could be some way outside the viewport.

As the API can't handle the requirement, it would probably be better to
use the API to capture the position of the click -- there must be a
hack to do that if click co-ordinates aren't directly available -- and
then use MySQL's spatial capability to determine the polygon which
contains the point. That is, in the listener function, set the document
URL to that of a script which can use the co-ordinates passed as
parameters to query the database. The end result will be the name of
the parish. Where we came in was getting that name as a tooltip as the
mouse is moved over the map, but a click to trigger it is likely to be
more useful.

Unless there are better ideas...

Andrew