title: C#_EventLog Exception
body: <p>I’m trying to write a simple event log but i confront with “System.Security.SecurityException: The source was not found...” 
  and i searched a lot but couldn’t find an efficient solution, I really really appreciate if someone help me with that 
  I know that the source needed to be created and the key must be registered but what is the key and
  How should i do that?</p>
  
  <pre><code>String source =“DemoTestApplication”;
  String log = “DemoEventLog”;
  EventLog demolog=new EventLog(log);
  EventLog demolog=new EventLog(log);
  demolog.Source=source;
  demolog.writeEntry(“This is the first message to the log”,EventLogEntryType.Information);
  </code></pre>