function mutation(arr) {
  newStr = [];
  valStr = [];
  newStr = arr[0].split('');
  valStr = arr[1].split('');

  //make all lowercase for string
  for(i = 0; i < newStr.length; i++){
  holder = newStr.shift();
  holder = holder.toLowerCase();
  newStr.unshift(holder);
  }

  for(i = 0; i < valStr.length; i++){
  //make all lowercase for target
  holder2 = valStr.shift();
  holder2 = holder2.toLowerCase();
  valStr.unshift(holder2);
  }

  counter = '0';

  for(i = 0; i < valStr.length; i++){
      n = newStr.indexOf(valStr[i]);
      if(n < 0){
          return false;
      }
      counter++;
    }
    return true;
}

mutation(["hello", "hey"]);

/*
mutation(["hello", "hey"]) should return false.  x
mutation(["hello", "Hello"]) should return true. x
mutation(["zyxwvutsrqponmlkjihgfedcba", "qrstu"]) should return true. x
mutation(["Mary", "Army"]) should return true.   x
mutation(["Mary", "Aarmy"]) should return true.  x
mutation(["Alien", "line"]) should return true.  x
mutation(["floor", "for"]) should return true.   x
mutation(["hello", "neo"]) should return false.  x
*/