title: Cannot connect to mysql with 127.0.0.1
body: <p>With the following code I can connect to mysql:
  <code>mysql_connect("localhost","username","");</code></p>
  
  <p>But if I change <code>localhost</code> to <code>127.0.0.1</code> I get the following error:</p>
  
  <p>Can't connect to MySQL server on '127.0.0.1' (13)</p>
  
  <p>Why doesn't it work with 127.0.0.1?</p>