Really Dynamic Master Pages

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace DynamicMasterPages
{
    public partial class Default2 : System.Web.UI.Page
    {
        protected void Page_PreInit(object sender, EventArgs e)
        {
            object cphnum = HttpContext.Current.Session["cphnum"];
            if (cphnum == null || !(cphnum is int))
                return;
            int num = (int)cphnum;
            //create the content for the pages
            for (int i = 1; i < num + 1; i++)
                base.AddContentTemplate("ContentPlaceHolder" + i.ToString(), new CompiledTemplateBuilder(new BuildTemplateMethod(this.Build)));
        }

        private void Build(Control c)
        {
            Literal b = new Literal();
            b.ID = "Literal1";
            b.Text = "Page";
            c.Controls.Add(b);
        }
    }
}