using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

/// <summary>
/// Summary description for BasePage
/// </summary>
public class BasePage: System.Web.UI.Page
{

    private void Page_PreRender(object sender, EventArgs e)
    {
        if (this.Title == "Untitled Page" || string.IsNullOrEmpty(this.Title))
        {
            throw new Exception("Page title cannot be \"Untitled Page\" or an empty string.");
        
        }
  
    }

    private void Page_PreInit(object sender, EventArgs e)
    {
        HttpCookie preferredTheme = Request.Cookies.Get("PreferredTheme");
        if (preferredTheme != null)
        {
            Page.Theme = preferredTheme.Value;
            
        }
    
    }



	public BasePage()
	{
        this.PreRender += new EventHandler(Page_PreRender);
        this.PreInit += new EventHandler(Page_PreInit);
	}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : BasePage
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
}