Remove duplicates from array

gistfile1.txt

/**
 * Remove duplicates from array
 * @param {Object} num
 */
function removeDup(num){
  cleaned = [];
  original = num;
  for(i=0;i<original.length;i++){
    if (cleaned.indexOf(original[i]) === -1){
      cleaned.push(original[i]);
    }
  }
  console.log('Remove duplicates: ' + cleaned);  
}

num=[7, 1,2,7,7,7,3,4,4,5,5,6,2,1,1,2,3];
removeDup(num);