title: Php check string for correct format
body: <p>Looking for some help on how to validate a string in PHP.</p>
  
  <p>My string contains:</p>
  
  <ul>
  <li>4 NUMBER</li>
  <li>1 LETTER </li>
  <li>5 NUMBER</li>
  </ul>
  
  <p>all in one entry, so  like <code>1234A12345</code>.</p>
  
  <p>I need to make sure/validate this before inserting in the DB.</p>
  
  <p>Can one of the wizard help me out there?</p>