Private mlngUserChoice As Long

Private Sub btnCancel_Click()
    mlngUserChoice =  1 
    Me.Visible = False
End Sub

Private Sub btnOk_Click()
    mlngUserChoice =  2 
    Me.Visible = False
End Sub

Private Sub Form_Unload(Cancel As Integer)
    Cancel = Me.Visible
    Me.Visible = False
End Sub

Public Property Get UserChoice() As Long
    UserChoice = mlngUserChoice
End Property

DoCmd.OpenForm  "Форма1" , , , , , acDialog
If IsFormOpen( "Форма1" ) Then
    Debug.Print Forms![Форма1].UserChoice
    DoCmd.Close acForm,  "Форма1" 
Else
    Debug.Print  "Потерялась куда-то..." 
End If