Public Class DataClass
    Private privateMyData As String = ""
    Private privateMoreData As String = ""

    Public Event MyDataChanged As EventHandler
    Public Event MoreDataChanged As EventHandler
    Public Property MyData() As String
        Get
            Return privateMyData
        End Get
        Set(ByVal Value As String)
            privateMyData = Value
            RaiseEvent MyDataChanged(Me, New EventArgs)
        End Set
    End Property
    Public Property MoreData() As String
        Get
            Return privateMoreData
        End Get
        Set(ByVal Value As String)
            privateMoreData = Value
            RaiseEvent MoreDataChanged(Me, New EventArgs)
        End Set
    End Property
    Public Sub Reset()
        MyData = ""
        MoreData = ""
    End Sub
End Class

Module modGeneral
    Friend DataStuff As DataClass
    Friend MyForms As New Collection
    Friend localNextData As String
    Sub AddForm(ByVal ThisForm As Form)
        MyForms.Add(ThisForm, ThisForm.Name)
        UpdateControlsNextData(localNextData)
    End Sub

    Friend Property NextData() As String
        Get
            Return localNextData
        End Get
        Set(ByVal Value As String)
            localNextData = Value
            UpdateControlsNextData(localNextData)
        End Set
    End Property

    Private Sub UpdateControlsNextData(ByVal Value As String)
        Dim frm As frmBase
        Dim obj As Object
        
        For Each obj In MyForms
            frm = CType(obj, frmBase)
            If Not IsNothing(frm.txtNextData) Then
                frm.txtNextData.Text = Value
            End If
        Next
    End Sub
End Module

Friend MyFormsToUpdate As New Collection
Private ControlsToUpdate() As String = _
  {"txtCustomer", "txtAddress", "txtName"}

Friend Sub AddFormToUpdate(ByVal ThisForm As Form)
  Dim ctrl As Control
  Dim i As Integer
  Dim AddThisForm As Boolean = False

  Try
    For Each ctrl In ThisForm.Controls
      For i = 0 To ControlsToUpdate.GetUpperBound(0)
          If ctrl.Name = ControlsToUpdate(i) Then
            AddThisForm = True
           Exit For
         End If
         If AddThisForm Then
           MyFormsToUpdate.Add(ThisForm, ThisForm.Name)
           Exit For
         End If
       Next
     Next
     If AddThisForm Then
       If MyFormsToUpdate.Count > 1 Then
         UpdateControlsOnAllForms( CType(MyFormsToUpdate(1), Form))
       End If
     End If
   Catch ex As Exception
     Throw New Exception( _
       "AddForm generated this error: " & ex.Message, ex)
   End Try
 End Sub

 Friend Sub UpdateControlsOnAllForms(ByVal MasterForm As Form)
   Dim frm As Form
   Dim ctrlMaster, ctrlClient As Control
   Dim i As Integer
   Try
   For Each frm In MyFormsToUpdate
     For Each ctrlMaster In MasterForm.Controls
       For i = 0 To ControlsToUpdate.GetUpperBound(0)
         If ctrlMaster.Name = ControlsToUpdate(i) Then
           For Each ctrlClient In frm.Controls
             If ctrlClient.Name = ControlsToUpdate(i) Then
               ctrlClient.Text = ctrlMaster.Text
                 Exit For
              End If
            Next
          End If
        Next
     Next
   Next
   Catch ex As Exception
     Throw New Exception( _
       "UpdateControlsNextData generated this error: " & ex.Message, ex)
     End Try
 End Sub