Mirroring Text Entry

[Gardner, Joseph A]

Apologies if this is too simple for me to find, but I'm looking for a way to mirror text from one field to another; that is, as a user enters text in a field, it is automagically entered in another field (and deleted if the text is deleted from the main field). I've searched the docs but can find no function for this and then tried to write a loop myself, but nothing comes of it. Appreciate any pointers or hints about getting this happening.

Many thanks in advance...

joe.