Save Session Timeout in Web.config as XML Document (edit)

using System;
using System.Diagnostics;
using System.IO;
using System.Xml;

namespace ConsoleApp11
{
 public class Program
 {
 public static void Main(string[] args)
 {
 string webConfigFilePath = @"C:\inetpub\wwwroot\WebApp\web.config";

 bool isSaveSuccess = SaveSessionTimeoutToWebConfig(webConfigFilePath, "480");
 }

 public static bool SaveSessionTimeoutToWebConfig(string filePathWebConfig, string sessionTimeout)
 {
 //
 // Change timeout from 30 to 1440
 // FROM: <sessionState timeout="30" />
 // TO: <sessionState timeout="1440" />
 // ----------
 // FROM:
 //<authentication mode="Forms">
 // <forms name="WebApp.CookieName" loginUrl="~/Login.aspx" protection="All" timeout="30" path="/" requireSSL="true" slidingExpiration="true" enableCrossAppRedirects="false" cookieless="UseDeviceProfile"></forms>
 //</authentication>
 // TO:
 //<authentication mode="Forms">
 // <forms name="WebApp.CookieName" loginUrl="~/Login.aspx" protection="All" timeout="1440" path="/" requireSSL="true" slidingExpiration="true" enableCrossAppRedirects="false" cookieless="UseDeviceProfile"></forms>
 //</authentication>

 try
 {
 if (File.Exists(filePathWebConfig))
 {
 XmlDocument doc = new XmlDocument();
 doc.Load(filePathWebConfig);

 XmlNode sessionState = doc.DocumentElement.SelectSingleNode("//system.web//sessionState");

 if (sessionState != null)
 {
 if (sessionState.Attributes["timeout"] != null && sessionState.Attributes["timeout"].Value == sessionTimeout)
 {
 //return true;
 }
 else
 {
 sessionState.Attributes["timeout"].Value = sessionTimeout;
 doc.Save(filePathWebConfig);
 }
 }

 XmlNode formsAuthentication = doc.DocumentElement.SelectSingleNode("//system.web//authentication//forms");

 if (formsAuthentication != null)
 {
 if (formsAuthentication.Attributes["timeout"] != null && formsAuthentication.Attributes["timeout"].Value == sessionTimeout)
 {
 return true;
 }
 else
 {
 formsAuthentication.Attributes["timeout"].Value = sessionTimeout;
 doc.Save(filePathWebConfig);
 }
 }
 }
 return true;
 }
 catch (Exception ex)
 {
 Debug.WriteLine(ex.ToString());
 return false;
 }
 }
 }
}