write time and comment to log file for recording a login or logout time.

lastlog.js

var a=WScript.arguments;
var f=WScript.CreateObject("Scripting.FileSystemObject");
var d=(new Date()).toLocaleString();
var c=(a.length>0)?a(0):"";
var n=WScript.ScriptFullName.replace(/\.\w+/,".txt");
var t=f.OpenTextFile(n,8,true);
t.WriteLine( d+" "+c );
t.Close();