how to use viewstate on other page

viewstate1.aspx
<asp:Label ID="Label1" runat="server" Text="first page of label"></asp:Label>

protected void Page_Load(object sender, EventArgs e)
    {
        ViewState["first"] = Label1.Text;
        Server.Transfer("viewstate2.aspx");
    }

    public StateBag ReturnViewState()
    {
        return ViewState;
    }


use on viewstate2.aspx.cs page

 protected void Page_Load(object sender, EventArgs e)
    {
        if (PreviousPage != null)
        {
            Label1.Text = "second page of label = " + PreviousPageViewState["first"].ToString();
        }
    }


    private StateBag PreviousPageViewState
    {
        get
        {
            StateBag returnValue = null;
            if (PreviousPage != null)
            {
                Object objPreviousPage = (Object)PreviousPage;
                MethodInfo objMethod = objPreviousPage.GetType().GetMethod("ReturnViewState");//System.Reflection class
                return (StateBag)objMethod.Invoke(objPreviousPage, null);
            }
            return returnValue;
        }
    }