how to make a level block/unblock

Hi everybody, I am Arkin160, but we don't care :) . I made a lot of research and I don't find what I need, that's why I ask the question here. I know the question was probably asked a lot of time, but i really need your help! I explain you the situation: I'm making a game in 2dand my menu is "in game":

I have 3 scripts; 2 in java et 1 in .txt and when you finish "level 1", there's a "1", which is in the .txt file (i called the .txt file "unlock level file.txt") with this script (I named it a.js but you can name it like you want).here is the a.js script:

 #pragma strict
 
 import System.IO;
 var filePath = "/Users/Shared/Unity/game/Assets/unlock level file.txt";
 var level : int;
  
 function OnTriggerStay2D(other : Collider2D){
     WriteFile(filePath);
 }
 
 function Start(){
     WriteFile(filePath);
 }
  
 function WriteFile(filepathIncludingFileName : String)
 {
     var sw : StreamWriter = new StreamWriter(filepathIncludingFileName);
     sw.WriteLine(level);
     sw.Flush();
     sw.Close();
 }

and that's working, but the problem is now with the b.js script:

 #pragma strict
 
 var dataFile : TextAsset; //.txt file
 var enter : GameObject; //trigger to load level x scene
 var red_plateform : GameObject; //green or red background of the level to see if it's unlocked or not
 var green_plateform : GameObject;
 
 function Start() {
      var returnChar = "\n"[0];
      var dataLines = dataFile.text;
      var buildDataPairs = new ArrayList();
      for (var dataLine in dataLines) {
          var dataPair = dataLine;
          buildDataPairs.Add(dataPair);
      enter.SetActive(false);
      red_plateform.SetActive(true);
      green_plateform.SetActive(false);
      }
      var dataPairs = buildDataPairs.ToArray();
          Debug.Log(dataPairs[0]);
          if(dataPairs[0] == 1){             // <----- the problem is here!
              enter.SetActive(true);
              red_plateform.SetActive(false);
              green_plateform.SetActive(true);
      }
 }

Just one request, please use javascript because i can't really use c#, but if you can't do this in java and you know how to do this in c#, please comment all lignes (what you do and what's the point), I'll get you my biggest thank's. if you have an other method you can propose, I'm opened at all propositions I hope you have all understand. if you have any questions I answer relatively quickly because I check the web site every 2 hours. Thank's a lot people! big heart on you :)

Greeting

Arkin160