Just put log.cs in appcode, create a folder in application root named ‘Logs’
log.cs
using System;
using System.Configuration;
using System.Data;
using System.IO;
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;
///
/// Summary description for Log
///
public class Log
{
#region Methods
public void WritetoLog(string strModule, string strRemarks)
{
// sLogDateFormat: take current date and time
string sLogDateFormat = DateTime.Now.ToString(“dd/MM/yyyy”) + ” ” + DateTime.Now.ToString(“HH:mm:ss”);
// sLogFileName: log file name for the module – user login with month and year
string sLogFileName = @”Error_Log_” + DateTime.Now.ToString(“MMMMyy”) + “.txt”;
// sLogFilePath: virtual path for storing the log file
string sLogFilePath = @”Logs/” + DateTime.Now.Year.ToString() + “/” + DateTime.Now.ToString(“MMMMyy”);
// check for existance of virtual path, if not create the pathin YYYY/MonthNameYYYY format, ex:- Logs/2008/July2008/
if (!Directory.Exists(sLogFilePath))
{
Directory.CreateDirectory(HttpContext.Current.Server.MapPath(sLogFilePath));
}
// open streamwriter to check existance of log filename, if notcreate the log file
StreamWriter sw;
if (!File.Exists(HttpContext.Current.Server.MapPath(sLogFilePath + “/” + sLogFileName)))
{
sw = File.CreateText(HttpContext.Current.Server.MapPath(sLogFilePath + “/” + sLogFileName));
sw.Flush(); // Flush the streamwriter object
sw.Close(); // Close the streamwriter object
sw = null;
}
//open streamwriter object to open the log file and appendremarls
StreamWriter writer = new StreamWriter(HttpContext.Current.Server.MapPath(sLogFilePath) + “/” + sLogFileName, true);
writer.WriteLine(sLogDateFormat + ” 
: ” + strModule + ” : ” + strRemarks); // write current date & remarks
writer.Close(); //close the streamwriter
writer = null;
}
#endregion Methods
}
.aspx.cs
try
{
//Your Function
}
catch (Exception ex)
{
StackFrame stackFrame = new StackFrame(0, true);
objLog.WritetoLog(stackFrame.GetFileName() + “_” + stackFrame.GetMethod().Name, ex.Message.ToString());
}
