C# -create A Custom Control For A Textbox?

i have used this coding to create a custom Control as my knowledge in the pervious post.i dono it is correct or not.I need a further help regarding this.so far i have used this coding the appcode->Number.cs in that i have used this coding further what should i do: my requriements is that i drag the textbox in the controls only number should be entered in that.for reference see my previous post:http://www.eggheadcafe.com/community/aspnet/2/10200401/how-to-create-a-dll-file-for-the-textbox-with-some-requriments.aspx.i need it in web applications

using System;
using System.Data;
using System.Configuration;
using System.Linq;

[code]...