I created a DialogWindow class that inherits from Coolite.Window that has an associated clientside Ext.ux.DialogWindow class. In the client class, I have a params property that's just an object. How can I create a clientconfig serverside property in my DialogWindow class that will serialize correctly? I tried:

        Private _URLParams As New Dictionary(Of String, String)
        ''' <summary>
        ''' Query string parameters to send to dialog
        ''' </summary>
        <ClientConfig("urlParams", JsonMode.UnrollCollection)> _
        <DefaultValue(CType(Nothing, Object))> _
        <Category("Config Options")> _
        Public Property URLParams() As Dictionary(Of String, String)
            Get
                Return _URLParams
            End Get
            Set(ByVal value As Dictionary(Of String, String))
                _URLParams = value
            End Set
        End Property
However, I don't see it as part of the rendered script. Is there anything special I need to do? In ASP.NET, dictionary(of string, string) is serialized as a javascript object.