protected void Page_Load(object sender, EventArgs e)
    {
        Session.Abandon();
        Session.Clear();
        Session.RemoveAll();
    }
.......
source code...........
<script type="text/javascript" language="javascript">
    function redir(){
    window.location="Default.aspx";
    
    }
    self.setTimeout(redir(),5000);
    
    </script>