Losing the session after the Postback
<p>I have been using session variables in my asp.net application for passing the next property:</p>

<pre><code>[DefaultValue(true)]
public bool IsModificationMode
{
    get
    {
        return (bool)Session["ModificationMode"];
    }
    set { Session["ModificationMode"] = value; }
}
</code></pre>

<p>In the PageLoad, I set it's value.</p>

<p>Now after the Postback, I am losing it's value having a a NullReferenceException</p>
