in 1st page/ page load
ViewState["orders"] = orders;

on form
 <asp:Button runat="server" ID="cmdTransfer" Text="view orders" OnClick="cmdTransfer_Click" Visible="True" />

the function button points to
 protected void cmdTransfer_Click(object sender, EventArgs e)
    {
        this.Context.Items["orders"] = ViewState["orders"];
        Server.Transfer("CrossPage2.aspx", true);
    }

2nd page
 orders= (List<Order>)this.Context.Items["orders"];