Newbie Q: Bound Database Controls and Exception handlers

Hi all,

  Thanks for reading this post.  I am new to Delphi, and have a basic
question regarding the user of exception handling and database items.  I
am looking at the sample applications DBAWARE1 and DBAWARE2.  As soon as
I try to add a new line to the DBgrid, I receive a message indicating
that an EDBEngineError has been raised.

  I know from RTFM'ing that I am supposed to wrap some code around a
try...finally block; however these examples have no code in them - they
are using 'bound' data controls.  My question then, boils down to this:

Where should one put error-handling code for bound items (to handle
things like missing or invalid data-entry fields), and what should that
code look like?  

I have been searching the online help to no avail; maybe I am looking in
the wrong place.  I would like to know what error(s) to look for; where
to put the code (I have tried the BeforePost event with no luck - the
.Cancel method doesn't seem to cancel the insert ).

TIA for your help...

Jim Gilbert               
Monsanto Co.                    
St. Louis, MO