How to delete Location Tag (Node) programmatically using its Path in Web.Config file using C# in ASP.Net

Please refer this code

HTML

Location path
<br />
<asp:TextBox ID="txtLocationPath" Text="Page1.aspx" runat="server" />
<br />
User Name
<asp:TextBox ID="txtUserName" runat="server" Text="Admin" />
<br />
<asp:Button Text="Delete" runat="server" OnClick="DeleteRoles" />

Webcofig

<?xml version="1.0"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
    <location path="Page1.aspx">
        <system.web>
            <authorization>
                <allow users="Admin,User1" />
                <deny users="*" />
            </authorization>
        </system.web>
    </location>
    <system.web>
        <compilation debug="true" targetFramework="4.0" />
    </system.web>
</configuration>

C#

protected void DeleteRoles(object sender, EventArgs e)
{
    string path = Server.MapPath("~/Web.Config");
    XmlDocument xDoc = new XmlDocument();
    xDoc.Load(path);
    XmlNodeList list = xDoc.DocumentElement.SelectNodes("location");
    if (list.Count > 0)
    {
        if (list[0].Attributes["path"].Value == this.txtLocationPath.Text.Trim())
        {
            //get authorization Node.
            XmlNode authorization = list[0].ChildNodes[0].ChildNodes[0];
            foreach (XmlNode node in authorization)
            {
                if (node.Name.ToLower() == "allow")
                {
                    string users = node.Attributes["users"].Value;
                    string data = string.Empty;
                    if (users.Split(',') != null)
                    {
                        string[] usersArray = users.Split(',');
                        foreach (string s in usersArray)
                        {
                            if (s != this.txtUserName.Text.Trim())
                            {
                                data += s + ", ";
                            }
                        }
                        data = data.Remove(data.LastIndexOf(","));
                        node.Attributes["users"].Value = data.Trim();
                        XmlTextWriter xwriter = new XmlTextWriter(path, null);
                        xDoc.WriteTo(xwriter);
                        xwriter.Close();
                        break;
                    }

                }

            }
        }
    }
}