Saveing then loading the last unlocked level with continue button

I'm trying to save the game everytime the player reaches a portal and then when the game is stopped and when player wants to play again he can press the continue button on the startmenu to start at the level he last unlocked.

here is the tutorial: http://unity3d.com/learn/tutorials/modules/beginner/live-training-archive/persistence-data-saving-loading

here is one of the scripts on the portal that should save the game:

 using UnityEngine;
 using System.Collections;
 
 public class Saving : MonoBehaviour {
     void OnTriggerEnter(Collider other) {
         if(other.gameObject.CompareTag("Player")){
             GameControl save = GetComponent<GameControl>();
             save.Save();
             }
         }
     }

gives no errors.

here is the script for the continue button:

 using UnityEngine;
 using System.Collections;
 
 public class ContinueCS : MonoBehaviour {
 
 void OnMouseUp(){
     GameControl.control.Load();
     int levelcount =  GameControl.control.levelcount;
 
     if(levelcount == 0){
         Application.LoadLevel("Level1");
     }
     else
     {
         Application.LoadLevel(levelcount);
     }
 }
 }

no errors

and here is the script based on the tutorial:

 using UnityEngine;
 using System.Collections;
 using System;
 using System.Runtime.Serialization.Formatters.Binary;
 using System.IO;
 
 public class GameControl : MonoBehaviour {
     public static GameControl control;
 
     public float score;
     public int levelcount;
 
     void Awake () {
         if(control == null)
         {
             DontDestroyOnLoad(gameObject);
             control = this;
         }
         else if(control != this)
         {
             Destroy(gameObject);
         }
     }
 
     public void Save()
     {
         BinaryFormatter bf = new BinaryFormatter();
         FileStream file = File.Create(Application.persistentDataPath + "/playerInfo.dat");
 
         PlayerData data = new PlayerData();
         data.score = score;
         data.levelcount = levelcount;
 
         bf.Serialize(file, data);
         file.Close();
     }
     public void Load()
     {
         if(File.Exists(Application.persistentDataPath + "/playerInfo.dat"))
         {
             BinaryFormatter bf = new BinaryFormatter();
             FileStream file = File.Open(Application.persistentDataPath + "/playerInfo.dat", FileMode.Open);
             PlayerData data = (PlayerData)bf.Deserialize(file);
             file.Close();
 
             data.score = score;
             data.levelcount = levelcount;
 
         }
     }
 }
 [Serializable]
 class PlayerData
 {
     public float score;
     public int levelcount;
 }

It would be great if someone could tell me what i'm missing or doing wrong. Thanks in advance