title: Is PHP not case sensitive?
body: <p>I am using <a href="http://en.wikipedia.org/wiki/MySQL" rel="nofollow noreferrer">MySQL</a> and <a href="http://en.wikipedia.org/wiki/PHP" rel="nofollow noreferrer">PHP</a>. In my database I have this table called <code>users</code>, and inside the <code>users</code> table have a record:</p>
  
  <p>username: admin</p>
  
  <p>password: password</p>
  
  <p>In my login page, I tried login as (password: password):</p>
  
  <ul>
  <li>username : ADMIN -> result : can login</li>
  <li>username : admin -> result : can login</li>
  </ul>
  
  <p>I store the username in my database as "admin", all lowercase.</p>
  
  <p>In my PHP authentication page, I didn't include the strtolower() function. Does it mean, in PHP the username form field that I submitted is not case sensitive?</p>