' Change Timer value from default of 0 to something like 200 

Private Sub Form_Timer()
' error trap is used to process situations when a form is clicked outside of the popup form
On Error GoTo NotForm:

    If Me.Name = Screen.ActiveForm.Name Then Exit Sub

NotForm:
    DoCmd.Close acForm, Me.Name, acSaveNo
End Sub

Make popup form close when user clicks outside of it

Visual Basic