Ok, I hear what you say. You have several opertors all picking a record
from the table, and you don't want two of them to pick the same record
at the same time.

First, Access 2003 does have optional, true, record-level locking. But
personally, I'm not sure I'd want to rely on that.

The problem with setting a flag in the record, is two-fold. (1) You'd
get locking conflicts anyway, when two operators pick the same record
at the same time. (2) What if the db sets a flag & then the db fails?
Maybe that flag will never get un-set, despite the fact that no
operator has actually contacted that record yet.

Here's what I'd try. See if code like the following will successfully
establish a temporary lock on the record, that can be seen by other
operators. ?????? represents the options that you'd have to play-around
with. If this worked, you'd just attach it o a "Lock this record"
button, or somesuch. If the db failed in the middle, all these locks
would naturally disappear.

(UNTESTED)

  dim db as database, rs as recordset
  set db = curentdb()
  on error resume next
  set rs = db.openrecordset ( "SELECT 1 FROM MYTABLE WHERE KEY=" &
me![key], ?????? )
  select case
      case 0 ' got it.
         ' continue.
      case ???  ' oops, someone else got it.
         msgbox "nope, someone else has this one!"
      case else ' other (unexpected) error.
         (whatever)
  end select
  on error goto 0

I have to go in a moment, so I might not see yor rply for several
hours.

HTH,
TC

It can't be quite the reason I thought, because then the problem would  
have gone away <g>

Then the "locking" status has three possible states: AlreadyContacted,
AttemptingRightNow, AvailableForContact. Your problem is that the form's  
recordset is created at the time the form is opened, and you want to know  
the status of a particular record at the moment it becomes current for the  
form. I would see the way round this as basing it on a single-record  
query, and looking explicitly for the next available record at the time.

In the form_load event, you could do this:

  lookup the RecordID for the first record:
    WHERE status=AvailableForContacting
      AND DateDiff("n", Now(), TimeOfLastContact) > 5 minutes
      AND RecordNumber > LastRecordNumberEditedByThisUser

  If there's no record, try the same query without the third criterion;  
i.e. start again from the top of the table.

  update that record to set its Status to BeingContacted
  create a SELECT query on that one record
  Set Me.RecordSource to that query

  If there are no records left, then msgbox the user and
  Set Cancel = True

In the cmdNextRecord_Click event,

  ' remember when the last contact was made
  me!TimeOfLastContact = now()
  me.Dirty = False ' save the record

  Call Form_Load(Cancel)
  If Cancel = True then docmd.Close a_form, me.name

This just selects the next available record using the same code as before.  
Remember to allow the form to close if there are no contacts left.

Hope that helps

Tim F