public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) // If page loads for first time { Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString()); // Assign the Session["update"] with unique value

        //=============== Page load code =========================





        //============== End of Page load code ===================
    }

}



protected void Button1_Click(object sender, EventArgs e)
{
    if (Session["update"].ToString() == ViewState["update"].ToString())    // If page not Refreshed
    {
        //=============== On click event code =========================

        Label1.Text = TextBox1.Text;
        //lblDisplayAddedName.Text = txtName.Text;


        //=============== End of On click event code ==================

        // After the event/ method, again update the session  
        Session["update"] = Server.UrlEncode(System.DateTime.Now.ToString());
    }
    else  // If Page Refreshed
    {
        // Do nothing 
    }
}
protected override void OnPreRender(EventArgs e)
{
    ViewState["update"] = Session["update"];
}

} this is not working for high resolution gradient background