Create Error Log in ASP.NET - Exception handling

How to log your errors in asp.net C#

There are many methods to log errors for example send errors via mail or keep in text file. This is an example to how to log errors in text file.

Class file to save Exception.

In this class there is one function ErrorLog parameter of error log is Exception
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;


public class LogError
{
public LogError()
{
public static void ErrorLog(Exception er)
{
try
{
string path = HttpContext.Current.Server.MapPath("errorlog.txt");
if (!System.IO.File.Exists(path))
{
using (System.IO.StreamWriter sw = System.IO.File.CreateText(path))
{
sw.WriteLine("Error :" + DateTime.Now.ToString());
sw.WriteLine(er.Source + er.Message + er.StackTrace);
sw.WriteLine("******************************************************");
}
}
else
{
using (System.IO.StreamWriter sw = System.IO.File.AppendText(path))
{
sw.WriteLine("Error :" + DateTime.Now.ToString());
sw.WriteLine(er.Source + er.Message + er.StackTrace);
sw.WriteLine("******************************************************");
}
}
}
catch
{
}
}
}