I am a newbie at VB4. While using data control, and the commands
data1.recordset.addnew and data1.recordset.update, I ran into the above
runtime error 3426 : The command was cancelled by an associated object.
Other commands such as data1.recordset.move.... and ...find work fine. Can
anyone help ?

Are you putting the data from the control in a bound grid or some other
object and then changing the data?

3426 is a four-letter word.  It means that something has failed to pass
a validation of some sort and been rejected.  Sometimes it was right to
fail; sometimes the failure is itself in error.  It's so obscure that
it's hard to get specific help - all the causes seem to be particular to
an individual user.

I suggest you eliminate one data item after another until the problem
goes away (tedious but it works) and then examine verrrrry carefully the
bit which, when removed, makes the program work.  Sometimes you have to
do odd things - I fixed one of these by changing the field from fixed to
variable length!

In your other subs change
Data1.Edit
Data1.whatever
data.update
change to
If ValidateFlag=False then
  Data1.edit
  data1.whatever
  data1.update
end if

This will make sure that you don't accidently call an update during a
validate event.