How to get asp:textbox value on code behind file?
<p>The error I get is :The name agentName does not exist in the current context"</p>

<p>On default.aspx I have <code>&lt;asp:TextBox ID="agentName" runat="server" /&gt;</code></p>

<p>On code behind file I have <code>agentName.Text</code></p>

<p>But is says the above error message.</p>

<p>when I pass hard coded value like "John", it works. I need a way to recognize the textbox on code-behind.</p>

<p>Thanks</p>

<p>Following is my code:</p>

<p>Default.aspx:</p>

<pre><code>//code behind on @page directive
&lt;%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="WebApplication2.WebForm1"%&gt;

// Getting the value from XML
 Agentname.Text = root.SelectSingleNode("name").ChildNodes[0].Value; 

// Assigned a textbox
asp:TextBox ID="Agentname" runat="server" disabled="true" MaxLength="57" /
(removed angel bracket as SO is ignoring this line, don't know why)

//Code behind

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

namespace WebApplication2
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        public void SaveXml(object sender, EventArgs e)
        {
            XDocument xmlDoc = XDocument.Load(Server.MapPath("Agent.xml"));
            Console.WriteLine("read XML");
            var person = xmlDoc.Descendants("agent");
            person.ElementAt(0).Value = "";

            xmlDoc.Element("agent").Add(new XElement("name", Agentname.Text));

            xmlDoc.Save(Server.MapPath("Agent.xml"));



        }
    }
}
</code></pre>
