How to check for a new session in aspx page?
<p>How to check for a new session in aspx page? And what is the difference between below three lines of checking session  </p>

<pre><code>1. if (Session["DETAILS"] == null) 
2. if (Session["DETAILS"] == "")
3. if (Session["DETAILS"].ToString() == "new")
</code></pre>

<p>Please help me how to check session in a page load event of aspx page. So I need that if session is new I need to enter new values. If session is edit I need to edit the values already present .</p>
