title: php SESSION variables on bluehost
body: <p>Im having problems with my php SESSION varialbles 
  my authentication system worked fine on my xampp server, and now im having problems since i moved over to bluehost </p>
  
  <p>normally, if i open a page like index.php it checks to see if you are logged in, and if your not sends you to the login page, but that isn't working 
  and just for testing i tried echoing the <code>$_SESSION['username']</code> and it turns up blank </p>
  
  <p>now i did what ALEX said and i got this error:
  Cannot modify header information - headers already sent by (output started at /home7/.../public_html/blog.php:4) in /home7/blogboua/public_html/blog.php on line 22</p>
  
  <p>here is the code:</p>
  
  <pre><code>&lt;?php session_start(); ?&gt;
  &lt;html&gt;
  &lt;head&gt;
  &lt;?php
  ini_set('display_errors', 'on');
  error_reporting(E_ALL);
  /*-----Connect to Database-----*/
   include ('connect_database_2.php');
  
  //check if logged in
  function isLoggedIn()
  {
      if(isset($_SESSION['valid']) &amp;&amp; $_SESSION['valid'])
          return true;
      return false;
  }
  
  
  //if the user has not logged in
  if(!isLoggedIn())
  {
      header('Location: login_form.html');
      die();
  }
  
  /* get username */
  $username = $_SESSION['username'];
  
  
  /*-----Include Navigation------*/
  include ('frame.html');
  
  ?&gt;
  </code></pre>