Accessing control in child page

 Hi, i have to access all the contols ie labels,buttons in the codebehind page in asp.net 2.0.So that I am using the following code,but it is not accesing webcontrols,please help me
 
For Each ctrl As Control In Me.Controls

                If (TypeOf (ctrl) Is Label) Then


                    'If ctrl.GetType Is GetType(Label) Then
                    Dim lbl As Label = CType(ctrl, Label)

                   
                End If
         ...