Remove duplications from array in JavaScript

removeDuplicates.js

  function removeDuplicates(array) {

    var newArray = []; //create new array to store no duplicates
    var isDuplicated = false; //track duplicate indexes
    newArray.push(array[0]); //add first index to new array

    for (i=1; i <= array.length; i++) { //loop over entered array
      for (var x = newArray.length - 1; x >= 0; x--) { // loop over new array
        if (newArray[x] == array[i]){ //compare newArray to entered array to see if the current index value already exist in the array
          isDuplicated = true; //current array index has a duplicate value
          break;
        } else if (isDuplicated == false && x == 0 && array[i] != null) { //last index in array checked and the current index value is not a duplicate
          newArray.push(array[i]); //add value to new array
        }
      }
    }
    return newArray;
  }