using System;
using System.ComponentModel;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebControls
{
    [DefaultProperty("TimerInterval")]
    [ToolboxData("<{0}:TimerControl runat=server></{0}:TimerControl>")]
    public class TimerControl : System.Web.UI.Control, INamingContainer
    {
 [Browsable(true)]
 [Category("Behavior")]
 [DefaultValue("TimerPostBack")]
 [Description("The PostBack value.")]
 public string PostBackValue
 {
     get
     {
   object viewState = this.ViewState["PostBackValue"];

   return (viewState == null) ? "TimerPostBack" : (string)viewState;
     }
     set { this.ViewState["PostBackValue"] = value; }
 }
 [Browsable(true)]
 [Category("Behavior")]
 [DefaultValue(1000)]
 [Description("The timer interval, in milli-seconds (1000 = 1 second).")]
 public double TimerInterval
 {
     get
     {
   object viewState = this.ViewState["TimerInterval"];

   return (viewState == null) ? 1000 : (double)viewState;
     }
     set { this.ViewState["TimerInterval"] = value; }
 }

 protected override void OnPreRender(EventArgs e)
 {
     StringBuilder sbScript = new StringBuilder();

     sbScript.Append("\n<script language=\"JavaScript\" type=\"text/javascript\">\n");
     sbScript.Append("<!--\n");
     sbScript.Append("\n");
     sbScript.Append("function autoPostBackTimer()\n");
     sbScript.Append("{\n");
     sbScript.Append("   " + this.Page.GetPostBackEventReference(this, this.PostBackValue) + ";");
     sbScript.Append("}\n");
     sbScript.Append("// -->\n");
     sbScript.Append("</script>\n");
     
     this.Page.RegisterClientScriptBlock(
   "TimerControlScript", sbScript.ToString());

     StringBuilder sbScript2 = new StringBuilder();

     sbScript2.Append("\n<script language=\"JavaScript\" type=\"text/javascript\">\n");
     sbScript2.Append("<!--\n");
     sbScript2.Append("window.setTimeout('autoPostBackTimer()', " + this.TimerInterval.ToString() + ")\n");
     sbScript2.Append("// -->\n");
     sbScript2.Append("</script>\n");

     this.Page.RegisterStartupScript(
   "TimerControlStartupScript", sbScript2.ToString());
 }
    }
}

private void Page_Load(object sender, System.EventArgs e)
 {
     if ( this.IsPostBack )
     {
   object eventArgument = this.Request["__EVENTARGUMENT"];
   if ( (eventArgument != null) && (eventArgument.ToString().Trim() == this.TimerControl1.PostBackValue) )
   {
       //Function or code to handle the elapse of the timer.
   }
   else
   {
       // Do Nothing
   }
     }

  Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       If Page.IsPostBack Then
           Dim eventarguement As Object = Me.Request("__EVENTARGUMENT")
           If Not eventarguement = Nothing And CStr(eventarguement).Trim() = Me.TimerControl1.PostBackValue Then
               'Code to Handle event
           Else
               ' Do Nothing
           End If

       End If
   End Sub