> How i can get old buffer value for some field?
> Example:
> table1.edit;
> table1.fieldbyname('t').asstring:='a';
> table1.fieldbyname('t').asstring:='b';
> How I can get value 'a'?

You can't. It is overwritten in the buffer.

table1.fieldbyname('t').Oldasstring; will return whatever the column was
when originally fetched from the server or whatever it was when last posted.

HTH,
Jason Wharton
CPS - Mesa AZ
http://www.ibobjects.com