title: Create Random Serial with PHP
body: <p>I want to have a random serial created on my website everytime someone visits.</p>
  
  <p>The format of the serial should be XXXXX-XXXXX-XXXXX-XXXXX.</p>
  
  <p>X represents a random number or capital letter.
  <br /><br /><br />
  Unfortunately I have no idea how to do this. Could anybody please help me out?</p>
  
  <p>So for example the random serial output could be: 3WT4A-NB34O-JU87P-B3UHS
  <br /><br /><br />
  Thanks a lot!</p>