     
     public func pauseSong()
     {
-        if audioPlayer!.playing {
-            audioPlayer!.pause()
+        if self.audioPlayer!.playing {
+            self.audioPlayer!.pause()
         }
     }
     
     public func stopSong()
     {
-        if audioPlayer == nil || !audioPlayer!.playing {
-            return
-        }
-        
-        audioPlayer!.stop();
-        if let event = playerDidStop {
+        if self.audioPlayer == nil || !self.audioPlayer!.playing {
+            return
+        }
+        
+        self.audioPlayer!.stop();
+        if let event = self.playerDidStop {
             event()
         }
-        if let current = currentSong {
+        if let current = self.currentSong {
             prepareAudio(current, current.index)
         }
     }
     
     public func playNextSong(stopIfInvalid stopIfInvalid: Bool = false)
     {
-        if let songs = songsList {
-            if let song = currentSong {
+        if let songs = self.songsList {
+            if let song = self.currentSong {
                 var index = song.index
                 
                 // Next song

            return
        }
        // Check the didStart event
        if let event = playerDidStart {
            event()
        }
        audioPlayer!.play()
    }
    
    public func playSong(index: Int, songsList: [AudioFile])

    
    public func playPreviousSong()
    {
        if let _ = self.songsList {
            if let song = self.currentSong {
                var index = song.index
                
                // Previous song
