In Microsoft Visual Studio 2005 or Visual Web Developer Express, create a new AJAX-enabled ASP.NET Web page and switch to Design view.

If the page does not already contain a ScriptManager control, in the AJAX Extensions tab of the toolbox, double-click the ScriptManager control to add it to the page.

In the toolbox, double-click the UpdatePanel control to add it to the page.

Click inside the UpdatePanel control and then double-click the Timer control to add it to the UpdatePanel control.

Note:
The Timer control can work as a trigger either inside or outside an UpdatePanel control. This example shows how to use the Timer control inside an UpdatePanel control. For an example of using a Timer control as a trigger outside an UpdatePanel control, see Walkthrough: Using the ASP.NET Timer Control with Multiple UpdatePanel Controls.

Set the Interval property of the Timer control to 10000.

The Interval property is defined in milliseconds, so that setting the Interval property to 10,000 milliseconds will refresh the UpdatePanel control every 10 seconds.

Note:
In this example, the timer interval is set to 10 seconds. That way, when you run the example, you do not have to wait a long time to see the results. However, each timer interval causes a postback to the server and causes network traffic. Therefore, in a production application, you should set the interval to the longest time that is still practical for your application.

Click inside the UpdatePanel control and then in the Standard tab of the toolbox, double-click the Label control to add it to the UpdatePanel control.

Note:
Make sure that you add the Label control inside the UpdatePanel control.

Set the label's Text property to Panel not refreshed yet.

Click outside the UpdatePanel control and double-click the Label control to add a second label outside the UpdatePanel control.

Note:
Make sure that you add the second Label control outside the UpdatePanel control.

Double-click the Timer control to create a handler for the Tick event.

Add code that sets the Text property of the Label1 control to the current time.

Create a Page_Load handler and add code that sets the Text property of the Label2 control to the time that the page is created.

Switch to Source view.

Make sure that the markup for the page resembles the following:

Partial Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Label2.Text = "Page created at: " & _
          DateTime.Now.ToLongTimeString()
    End Sub

    Protected Sub Timer1_Tick(ByVal sender As Object, ByVal e As System.EventArgs)
        Label1.Text = "Panel refreshed at: " & _
          DateTime.Now.ToLongTimeString()

    End Sub
End Class

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Label2.Text = "Page created at: " +
          DateTime.Now.ToLongTimeString();
    }
    protected void Timer1_Tick(object sender, EventArgs e)
    {
        Label1.Text = "Panel refreshed at: " +
          DateTime.Now.ToLongTimeString();
    }
}

Save your changes and press CTRL+F5 to view the page in a browser.

Wait at least 10 seconds for panel to refresh.

The text inside the panel changes to display the last time that the panel's content was refreshed. However, the text outside the panel is not refreshed.