how to get session varriable to work with a datagrid view in vb

hi im trying to get it so it will take the customer id from the previous page(orders.aspx) and use a sql select statement on my order confirmation.aspx page to select all the orders in my orders table and only display the ones that match the customer ID from the orders.aspx page., im trying to get it to display it in a datagrid view
 
i can get the page to load, but it doesnt show my datagrid view,
 
here is the code i have for this:-
 
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        If (Not Page.IsPostBack) Then

           
            Dim custID As Integer
            Dim strSessionID As String
        ...