the cursor is moved one space to the left and that screen position is erased
as if \fBdelch\fR had been called.
If the character value is any other \fBKEY_\fR define, the user is alerted
the cursor is moved one space to the left and that screen position is erased
as if \fBdelch\fR had been called.
If the character value is any other \fBKEY_\fR define, the user is alerted