Generate no duplicate digits
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/9960908/permutations-in-javascript">permutations in javascript?</a>  </p>
</blockquote>



<p>Now I have 6 numbers, they are from 1 to 6.
I want to generate some digits using all of these numbers, for example, 123456, 123465, how could I use JavaScript to solve that?</p>

<p>6 * 5 * 4 * 3 * 2 * 1, the program should generate 720 results;</p>
