i want to retrieve the data using data list control from a data base at regular time interval say for eg 1 min.

Controls:

        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <asp:Timer ID="Timer1" runat="server" Interval="1000" OnTick="Timer1_Tick">
                </asp:Timer>
                <asp:LinqDataSource ID="LinqDataSource1" runat="server" ContextTypeName="NorthWindDataContext"
                    EnableDelete="True" EnableInsert="True" EnableUpdate="True" TableName="Products">
                </asp:LinqDataSource>
                <asp:DataList ID="DataList1" runat="server" DataSourceID="LinqDataSource1">
                </asp:DataList>
            </ContentTemplate>
        </asp:UpdatePanel>

Code:

    protected void Timer1_Tick(object sender, EventArgs e)
    {
        DataList1.DataBind();
    }

Set the Interval property to specify how often postbacks will occur, and set the Enabled property to turn the Timer on or off. The Interval property is defined in milliseconds and has a default value of 60,000 milliseconds, or 60 seconds.

When a postback was initiated by the Timer control, the Timer control raises the Tick event on the server. You can create an event handler for the Tick event to perform actions when the page is posted to the server. In this event you can bind the data to DataList

http://www.asp.net/AJAX/Documentation/Live/overview/UsingTimerControlTutorial.aspx 

You can put the Ajax Timer control and DataList control into an updatepanel. You can set interval of timer to 1min or 2min.

Suggestion: To improve the performance of the page, I suggest you had better set interval to 3 or 5 min.