dmplayer mp3 player arduino

#include <DFPlayer_Mini_Mp3.h>
#include "SoftwareSerial.h"
SoftwareSerial mySerial(10, 11);
# define Start_Byte 0x7E
# define Version_Byte 0xFF
# define Command_Length 0x06
# define End_Byte 0xEF
# define Acknowledge 0x00 //Returns info with command 0x41 [0x01: info, 0x00: no info]

# define ACTIVATED LOW

int buttonNext = 2;
int buttonPause = 3;
int buttonPrevious = 4;
boolean isPlaying = false;



void setup () {
  pinMode(13, OUTPUT);
  pinMode(12, INPUT);
  Serial.begin( 9600 ) ;
  mySerial.begin (9600);
  delay(1000);
  //playFirst();
  //mp3_pause ();
  isPlaying = false;

  mp3_set_serial (mySerial);  //set softwareSerial for DFPlayer-mini mp3 module
  mp3_set_volume (15);


}



void loop () {
  if (digitalRead(12) == 1) {

    digitalWrite(13, 0);
    delay(5000);
    mp3_play (3);
    delay (90000);
  }
  else {
    digitalWrite(13, 1);
  }
}


// name songs to play [   mp3_play (3);   ] == [   ./mp3/0003.mp3   ]