Dictionnary.add()

having error NullReferenceExecption on lign: myLabels.Add(ctrl.name, ctrl)

Imports System.Collections.Generic

 Dim myButtons As Dictionary(Of String, Button)
 Dim myLabels As Dictionary(Of String, Label)
Private Sub frmRoom_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        For Each ctrl As Control In Me.Controls
            If TypeOf (ctrl) Is Button Then
                myButtons.Add(ctrl.name, ctrl)
            ElseIf TypeOf (ctrl) Is Label Then
                myLabels.Add(ctrl.name, ctrl)
            End If
        Next
End Sub


any ideas folks !?!!?