Replacing/avoiding page-reload prompts from POST method?

[John Geddes]

If a user tries a Refresh/Reload on a page that has been called as the
result of submitting a Form with the POST method, IE and Firefox both
throw up warning messages that are pretty confusing to the non-technical
user:

IE: "The page cannot be refreshed without resending the information ...."

Firefox: "The page you are trying to view contains POSTDATA ..."

I know that it can be avoided by using GET instead, but I really don't
want to do that.

Does anyone know a way of trapping these events in Javascript so that I
can write my own warning message (or even block the Refresh/Reload
altogether)?

John Geddes
England