Kohana file upload validation

kohana_file_validation.php

<?php
$file = Validation::factory($_FILES);

$file->rules(
  'curriculo',
  array(
    array(array('Upload', 'valid')),
    array(array('Upload', 'not_empty')),
    array('Upload::type', array(':value', array('jpg', 'png', 'gif')))
  )
);     
if ($file->check()){     
  $filename = explode('.', $_FILES['curriculo']['name']);
  Upload::save($_FILES['curriculo'],URL::title($filename[0],'-',true) .   '.'. strtolower($filename[1]),UPLOAD_PATH . 'curriculos/', 0777);     
}