End of playing audio file , using Naudio.dll

i'm using this code to play a wav file, but i don't know how to know when the audio file ends to do the next steps of my program. Example: When i click Play button, label Status = "Playing", and then, end of playing, label Status = "Stopped".

 //using
 using NAudio.Wave;

 //var
 WaveFileReader reader;
 DirectSoundOut output;

 // Play button
 output = new DirectSoundOut();
 reader = new WaveFileReader(@"D:\dmt.wav");
 output.Init(new WaveChannel32(reader));
 lab_Status.Text = "Playing...";
 output.Play(); 

I tried to use Stop event but it didn't work. Please help me, thanks.