Random numbers in an array

randomArray.js

/*Function to return an  array containing *length* random numbers 
and having the range from 0 to *max* */
function randomArray(length, max) {
    return Array.apply(null, Array(length)).map(function() {
        return Math.round(Math.random() * max);
    });
}

/* function than shuffle an array */
function shuffle(array) {
  var tmp, current, top = array.length;
  if(top) while(--top) {
    current = Math.floor(Math.random() * (top + 1));
    tmp = array[current];
    array[current] = array[top];
    array[top] = tmp;
  }
  return array;
}

resultArray = randomArray(20,500);
document.write(resultArray);
document.write("\n");
document.write(shuffle(resultArray));