Web Forms :: Way To Control Null When Inheriting From Class Library Class

I have this Control directive in a usercontrol (i've changed the namespace and class name):

<%@ Control Language="C#" AutoEventWireup="true" Inherits="Namespace.Path.To.ClassName" %>
<asp:TextBox runat="server" ID="txtComment" TextMode="MultiLine" ValidationGroup="comment" />
ClassName is a class that lives in a class library and this is the class:
namespace Namespace.Path.To
{
public class ClassName : System.Web.UI.UserControl
{
protected System.Web.UI.WebControls.TextBox txtComment;
protected void Page_Load(object sender, EventArgs e)
{
HttpContext.Current.Response.Write(txtComment == null);
HttpContext.Current.Response.End();
}