Hi Canie:

One problem with the rectangle format that is in the form now is that the rectangle must be NS or EW oriented. If one wanted to define an area for the southern San Andreas, a NS or EW oriented rectangle would include a lot of additional real estate that the predictor probably wouldn't want. Rather than defining a rectangle as you are doing now, I would suggest the form request that the predictor enter the Northernmost and Southernmost Lon/Lat pairs of opposite corners of the rectangle. This will allow for rectangles at any NS/EW orientation, and would allow you to define a long narrow rectangle that hugs the southern San Andreas for example. Of course squares would be accomodated as they are just a rectangle with 4 equal sides. Wording could be something like:

"Enter longitude and latitude for the northernmost and southernmost corners of a rectangle. If the rectangle is oriented perfectly NS or EW, enter longitude and latitude for any opposite two corners."

I think this would allow for much more flexibility for defining areas without getting into polygons.

Michael