Flatten nested arrays

gistfile1.txt

/*
 *  Flatten a multidimentional array of integers to a single dimention with the integer values
 */
function flatten_array(arr) {
  var newArr = []
  for (var idx=0; idx<arr.length; idx++) {
    if (Array.isArray(arr[idx])) {
      var a = flatten_array(arr[idx]);
      for (var i=0; i<a.length; i++) {
        newArr.push(a[i]);
      }
    }
    else {
      newArr.push(arr[idx]);
    }
  }
  return newArr;
}