Q:

Unable to access User Control's child controls from code behind

I am trying to access some of the user controls' child controls from code behind.  Some of them is working while others not.  Faulty user controls don't have designer files.  I want to know if this is the reason?  If so then I can't create some of the controls from scratch as they are too complex and my designer sent them without designer file and I can't give him back the code to correct as he went outside town. 
Moreover they are looking great without designer file in design view.  But when I write something like this:
Button1.Visible=false;
It's showing Button1 does not exist in current context.  Please tell me how to solve this? 
Following is the markup of one of the faulty User-Control:
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="commentUI.ascx.cs" Inherits="commentUI" %>
<asp:Button ID="Button1" runat="server" Text="Button" />

Code-Behind file:
using System;
using System. Collections. Generic;
using System. Linq;
using System. Web;
using System. Web. UI;
using System. Web. UI.WebControls;

public partial class commentUI : System. Web. UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Button1.Visible = false;
    }
}

A:

With the help of hint from @raja I found the solution.  I updated Inherits property to Inherits="MyProjectNamespace. User_Controls.commentUI" and it worked.