title: short php code for random number string, 5 chars
body: <p>I'm having a problem, im trying to generate a 5 or 7 characters long number code with php,
  but the following code does include letters, i only need numbers, thanks in advance</p>
  
  <pre><code>$newgid = substr(md5(microtime()),rand(0,9),5);
  </code></pre>