Step 1.
Just create the table called something like, "OpenCount". Then, create a field that is an "Autonumber" type.
Step 2.
When the MDE starts up, it should launch either a form or an "autoexec" macro. If Autoexec, then have it launch your start-up code and add a conditional statement that makes a function call the following code (It may need some debugging!)..
' If this function returns TRUE, then limit reached.
Private Function OpenCount() as Boolean
DIm rcCount as Recordset
OpenCount = False
Set rcCount = Currentdb.OpenRecordset("OpenCount"

If Not rcCOunt.BOF then rcCOunt.MoveLast
If rcCount.RecordCount > 5 then
' notify user of open limit reached.
OpenCount = True
Else
rcCOunt.AddNew
rcCount.Update
rcCount.Close
End if
Set rcCOunt = nothing
End Function
I thought this up in a hurry. The reason why I am using an auto-number is (for some bizarre reason! I don't know! It just popped into my head!) to give some security that the table is not manipulated numerically.
Gary
gwinn7