title: How does PHP interpret Javascript's Null value?
body: <p>Sol let's suppose that we send a post query to a PHP file, 
  this query where we have ...&amp;title=title
  where title is for example  <code>title=$(#title).val();</code> (assuming we're including Jquery)
   in PHP we have <code>$title=$_POST['title'];</code>
  Let's suppose then that title is null , will PHP consider null as string  ? or something empty ? </p>