title: Parse value to a mysql Query
body: <p>I have this quick question, i have got the username variable from a form and i need to insert it in a query, can you please tell me where i'm going wrong, it says: Unknown column '$username' in 'field list'</p>
  
  <p>Here is the code:</p>
  
  <pre><code>echo $HTTP_POST_VARS['username'];
  
     echo $username;
     $query = sprintf( 'SELECT $username FROM hostess' );
  </code></pre>