Streamwriter returning Null Javascript

I'm having problems with Streamwriter. First off, Here is the way I'm getting the values for each line(I'm using Js) -

 while (true) {
 
  for (i = 0; i <= 1; ++i){
  input = "";
      input = sr.ReadLine();
      forward = input;
      Debug.Log(forward);
      }
 
  for (i = 1; i <= 2; ++i){
  input2 = "";
      input = sr.ReadLine();
      left = input;
    Debug.Log(left);
      }
 
  for (i = 2; i <= 3; ++i){
  input3 = "";
      input = sr.ReadLine();
      right = input;
      Debug.Log(right);
      }
 
  for (i = 3; i <= 4; ++i){
  input4 = "";
      input = sr.ReadLine();
      backward = input;
      Debug.Log(backward);
      }
 
 
 if (input == null) { break; }
  if (input2 == null) { break; }
   if (input3 == null) { break; }
    if (input4 == null) { break; }

Now for the problem. When ever I start the game, it loads all the values but then after the debug log shows that each value has been loaded. The last 3 turn null. What am I doing wrong?