Create Class Question

[lorena]

I am trying to create a class that can be invoked to create a bi-directional sort of any datagrid on the pages of the site I am working on.
This is only the second time I have ever tried this and I am getting errors in the code but I am not sure why.
I want to incorporate ViewState as part of the class.
This is my code:

Imports System.Web.UI.Page
Public Class clsSort
    Private Property SortExpression() As String
        Get
          Dim o As Object = ViewState("SortExpression")
          If o Is Nothing Then
            Return String.Empty
          Else
            Return o.ToString
          End If
        End Get

        Set(ByVal Value As String)
          ViewState("SortExpression") = Value
        End Set
      End Property

  Private Property SortAscending() As Boolean
        Get
          Dim o As Object = ViewState("SortAscending")
          If o Is Nothing Then
            Return True
          Else
            Return Convert.ToBoolean(o)
          End If
        End Get
        Set(ByVal Value As Boolean)
          ViewState("SortAscending") = Value
        End Set
      End Property
End Class

I included the System.Web in my Project references

This is my error message:
'System.Web.UI.Control.Protected Overridable Overloads ReadOnly Property ViewState() As System.Web.UI.StateBag' is not accessible in this context because it is 'Protected'

It seems like there should be a way to do this so I don't have to keep copying the code each time. I just can't quite figure it out.