title: session variables timeout in asp.net app
body: <p>In my web app I'm using some session variables, which are set when I login:</p>
  
  <p>e.g. <code>Session("user_id") = reader("user_id")</code></p>
  
  <p>I use this through my app.</p>
  
  <p>When the session variable times out, this throws errors mainly when connecting to the database as <code>session("user_id")</code> is required for some queries.</p>
  
  <p>How can I set my session variables so that once they are timed out to go to the login page or how can at least increase the length of time the are available?</p>