tkinter entry eat chars?

[phil]

In a Tkinter entry field (or Pmw entry)
how could I eat charactres?

Say a certain char is keyed in. Say &
I notice in the event handler for <key>.
I don't want any more charactres to display or
be in the field until I handle a see, in the
event handler, another character. Say ?

Can the event handler somehow destroy the char?

Thanks