How to handle the browser history while logout?
<p>I am using ASP.NET and C#.</p>

<pre><code>if (!IsPostBack)
        {
            if (Session["un"] == null)
            {
                Response.Redirect("Default.aspx");
            }
            else
            {
                Response.ClearHeaders();
                Response.AddHeader("Cache-Control", "no-cache, no-store, max-age=0, must-revalidate");
                Response.AddHeader("pragma", "no-cache");
            }
        }
</code></pre>

<p>I am using this in codebehind file of my masterpage.So that after logout, if the user click the browser back button, the page load function in masterpage is called.But without these line. </p>

<pre><code>  Response.AddHeader("Cache-Control", "no-cache, no-store, max-age=0, must-revalidate");
  Response.AddHeader("pragma", "no-cache");
</code></pre>

<p>that pageload function is not invoked while pressing browser back button.</p>

<p>Can someone explain these two lines?</p>

<p>Thanks.</p>
