Hi.i want to use a ajax updatepanel.on postnack i only want the datalist "dlEvnt" to get refreshed.but thats not happening.can anybody tell me what to do.
Here's my code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="news_evnts.aspx.cs" Inherits="news_evnts" %>

<%@ Register Assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
    Namespace="System.Web.UI" TagPrefix="asp" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Prison Department, Goa</title>
    <link rel="stylesheet" href="style.css" type="text/css" charset="utf-8" />

    <script language="javascript" type="text/javascript">
    function txtChk(){txtChanged('u'); txtChanged('p');}
		function txtChanged(s){if(s=='u'){if(document.getElementById("txtEmail").value=="" || document.getElementById("txtEmail").value=="Login Id"){document.getElementById("txtEmail").value="Login Id";	document.getElementById("txtEmail").style.color="#aca899";}}
		else if (s=='p') {if(document.getElementById("txtPass").value=="" || document.getElementById("txtPass").value=="Password"){document.getElementById("txtPass").value="Password";document.getElementById("txtPass").style.color="#aca899";}}}
		function txtClick(s){if(s=='u'){if(document.getElementById("txtEmail").value=="Login Id"){	document.getElementById("txtEmail").value="";document.getElementById("txtEmail").style.color="#000000";	}}
		else if(s=='p'){if(document.getElementById("txtPass").value=="Password"){	document.getElementById("txtPass").value="";document.getElementById("txtPass").style.color="#808080";}}}
  
  
			var lastColorUsed, colUsed;
			
			function dg_changeBackColor(row, highlight)
			{
				if (highlight)
				{
					lastColorUsed = row.style.backgroundColor;
					colUsed =  row.style.color;
					
					row.style.backgroundColor ='#747170';//"#F7F7F7";// 'papayawhip';
					row.style.color = 'WHITE';
					row.style.cursor='hand';
				}
				else
				{			
					row.style.backgroundColor = lastColorUsed;
					row.style.color = colUsed;
				}
			}
			
			function stopPost()
			{
				return false;
			}
			
		

    </script>

    <script type="text/javascript">

 function LoadDiv(url)

 {

    var img = new Image();

    var bcgDiv = document.getElementById("divBackground");

    var imgDiv = document.getElementById("divImage");

    var imgFull = document.getElementById("imgFull");

    var imgLoader= document.getElementById("imgLoader");

    imgDiv.style.display = "block"; 

    imgLoader.style.display = "block";

    img.onload = function() {

        imgFull.src = img.src;

        imgFull.style.display = "block";

        imgLoader.style.display = "none";

    };

    img.src= url;
    
     var width = "10px";

    //var width = document.body.clientWidth;

    if (document.body.clientHeight > document.body.scrollHeight)

    {
     bcgDiv.style.height = "10px";

       // bcgDiv.style.height = document.body.clientHeight + "px";

    }

    else

    {
    bcgDiv.style.height = "10px";

        //bcgDiv.style.height = document.body.scrollHeight + "px" ;

    }

 

//    imgDiv.style.left = "100px";

//    imgDiv.style.top =  "50px";
//    imgDiv.style.right = "100px";

//    imgDiv.style.bottom =  "50px";

    bcgDiv.style.width="10px";

    

    bcgDiv.style.display="block";

    imgDiv.style.display="block";

    return false;

 } 

 function HideDiv()

 {

    var bcgDiv = document.getElementById("divBackground");

   var imgDiv = document.getElementById("divImage");

    var imgFull = document.getElementById("imgFull");
    

    if (bcgDiv != null)

    {

        bcgDiv.style.display="none";

        imgDiv.style.display="none";

        imgFull.style.display = "none";

    }

 }

    </script>

    <script language="JavaScript" type="text/javascript">
			var newBg;
			function changeHl(strId)
			{
			   newBg = "images/HlImg/"+strId+".jpg";
			   document.getElementById("imgHL").src = newBg;		  
			}
			function setURL()
			{
		   var param = "height="+screen.height+",width="+screen.width+",resizable=yes,status=yes,toolbar=no,menubar=no,screenX=0,screenY=0,left=0,top=0";
			   var s =  document.getElementById("ctl00_txtFilePath").value ;	
			  window.open(s,"citizenchart",param);
			   
			}
    </script>

</head>
<body>
    <form id="mst" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <div id="wrapper">
            <div id="header">
                <div style="color: #FFFFFF; font-family: 'Maiandra GD', 'Trebuchet MS', Tahoma, Verdana;">
                    <table id="tbl" width="100%">
                        <tr>
                            <td align="center" style="width: 145px">
                                <img src="images/bg_charity1.jpg" alt="gov" style="width: 76px; height: 84px" /></td>
                            <td>
                                <div style="font-size: 24px;">
                                    Inspector General of Prisons</div>
                                <div style="font-size: 16px;">
                                    Government of Goa</div>
                            </td>
                        </tr>
                    </table>
                </div>
                <div id="navlist">
                    <ul id="Ul1">
                        <li><a id="hm" runat="server" href="index.aspx">Home</a></li>
                        <%--<li><a id="hm" href="index.html">Home</a></li>--%>
                        <li><a id="au" runat="server" href="AboutUs.aspx">About Us</a></li>
                        <li><a id="am" runat="server" href="Amenities.aspx">Amenities</a></li>
                        <li><a id="ne" runat="server" href="news_evnts.aspx">News & Events</a></li>
                        <li><a id="pr" runat="server" href="jailproducts.aspx">Products</a></li>
                        <li><a id="rti" runat="server" href="rghtoinfrmtn.aspx">R. T. I.</a></li>
                        <li><a id="cc" runat="server" href="remission.aspx">Remission</a></li>
                        <li><a id="fb" runat="server" href="Default2.aspx">Feedback</a></li>
                        <li><a id="cu" runat="server" href="contact.aspx">Contact Us</a></li>
                    </ul>
                </div>
            </div>
            <div id="headline">
                <div id="photo">
                    <div>
                        <img src="images/igp.gif" width="618" height="250" alt="Pic 1" />
                    </div>
                </div>
                <div id="search-news" style="height: 248px">
                    <h2 class="downcast">
                        Quick Links</h2>
                    <br />
                    <div id="plussbullets">
                        <asp:HiddenField ID="txtFilePath" runat="server" />
                        <%--    <asp:TextBox ID="txtFilePath" runat="server" Width="71px"  ></asp:TextBox>--%>
                        <ul>
                            <%--  <li> <asp:LinkButton ID="lbStats" runat="server" OnClick="stats_Click" >Prison Statistics</asp:LinkButton></li>--%>
                            <%--<li><asp:HyperLink ID="HyperLink1" runat="server"  OnClick="stats_Click">Prison Statistics</asp:HyperLink></li>--%>
                            <%-- <li><a href="" onclick="stats_Click">
                              Prison Statistics  </a></li>--%>
                            <li><a id="A1" href="" runat="server" onclick="setURL();" target="_blank">Prison Statistics</a></li>
                            <li><a href="rightsandduties.aspx">Rights & Duties of Prisoners</a></li>
                            <li><a href="reformation.aspx">Jail Reformation</a></li>
                            <li><a href="Citizen_new.pdf" target="_blank">Citizen's Charter</a></li>
                            <li><a href="listaddoff.aspx">List of area wise offices and Judicial Lock-Ups</a></li>
                            <li><a href="orgchart.aspx">Organisational Setup</a></li>
                        </ul>
                    </div>
                </div>
                <div class="clear">
                </div>
            </div>
            <div id="body">
                <div>
                    <div class="info">
                        News and Events</div>
                    <br />
                    <div style="width: 200px; float: right; padding: 2px 2px 2px 2px">
                        <div style="height: 400px; width: 200px; overflow: Auto;">
                            <asp:DataList ID="dlEvents" runat="server" Width="180px" GridLines="both" CellPadding="5"
                                OnItemCommand="getSelected" DataKeyField="prison_event_id">
                                <SelectedItemStyle BackColor="White" ForeColor="#99A866" />
                                <ItemTemplate>
                                    <div style="background-image: url(images/bullet_plus.gif); background-repeat: no-repeat">
                                        <div style="margin-left: 20px; padding-bottom: 2.5px;">
                                            <asp:LinkButton ID="btnlEvntId" runat="server" Visible="false" CommandName="select"
                                                Text='<%# Bind("prison_event_id") %>' />
                                            <asp:LinkButton ID="btnlEvntTitle" runat="server" CommandName="select" Text='<%# Bind("prison_event_title") %>' />
                                        </div>
                                    </div>
                                </ItemTemplate>
                                <ItemStyle BackColor="White" ForeColor="#99A866" Font-Names="Tahoma, Verdana, sans-serif"
                                    Font-Size=" 12px" Font-Bold="true" />
                                <HeaderTemplate>
                                    <table bgcolor="white">
                                        <tr style="font-family: Tahoma, Verdana, sans-serif; font-size: 14px; font-weight: bold;
                                            background-color: #5C5C5C">
                                            <td>
                                                LIST OF EVENTS</td>
                                        </tr>
                                        <tr>
                                            <td colspan="3">
                                                <div style="overflow: scroll; height: 250px; width: 180px; font-size: 15px">
                                                    <table bgcolor="white" width="180px">
                                                        <%--<div> Titles</div>--%>
                                </HeaderTemplate>
                                <HeaderStyle BackColor="#5C5C5C" BorderColor="#859D31" BorderStyle="Solid" BorderWidth="1px"
                                    Font-Names="Tahoma,Verdana,sans-serif" Font-Bold="True" Font-Size="11px" ForeColor="White" />
                                <FooterTemplate>
                                    </table></div></td></tr></table></FooterTemplate>
                            </asp:DataList>
                        </div>
                    </div>
                    <%-- style="width: 351px; height:351px"--%>
                    <div style="width: 550px; float: left;">
                        <table border="0" id="tblEvntDetails" runat="server" visible="false" width="540px">
                            <tr>
                                <td colspan="4" style="background-color: #5C5C5C; font: bold 18px Tahoma, Verdana, sans-serif;
                                    color: White; padding-bottom: 2px">
                                    <asp:Label ID="lblEvntTitle" runat="server" Text='<%# Eval("prison_event_title") %>'
                                        Visible="false"></asp:Label>
                                </td>
                            </tr>
                            <tr>
                                <td colspan="4">
                                    <asp:ImageButton ID="btniEvntDtlImg" Height="350" Width="540" runat="server" />
                                </td>
                            </tr>
                            <tr>
                                <td colspan="4" style="font: bold 11px Tahoma, Verdana, sans-serif; padding-bottom: 4px">
                                    <asp:Label ID="lblEvntDtlDesc" ForeColor="#5C5C5C" runat="server" Text='<%# Bind("prison_eventDtl_description") %>'
                                        Width="535px"></asp:Label>
                                </td>
                            </tr>
                            <tr>
                                <td colspan="4" style="width: 540px">
                                    <asp:UpdatePanel ID="updpEvnt" runat="server" UpdateMode="Conditional">
                                        <ContentTemplate>
                                            <%--OnSelectedIndexChanged="selectedIndexChanged" "--%>
                                            <asp:DataList ID="dlEvnt" runat="server" HorizontalAlign="Left" RepeatDirection="Horizontal"
                                                BorderColor="#99A866" RepeatColumns="3" GridLines="Both" OnItemCommand="imageSelect"
                                                DataKeyField="prison_eventDtl_srno" Visible="false">
                                                <ItemTemplate>
                                                    <table width="100%" onmouseover="dg_changeBackColor(this, true);" onmouseout="dg_changeBackColor(this, false);">
                                                        <tr>
                                                            <td align="center" colspan="4">
                                                                <asp:ImageButton ID="imgDlEvnt" runat="server" Height="51px" Width="66px" AlternateText="Photo"
                                                                    BorderColor="Silver" BorderStyle="Solid" ImageAlign="Middle" ImageUrl='<%# "~/ASHX/ImageHandler.ashx?queryType=dl_image&__KEY="+ Eval("prison_event_id")+"&__imgId="+Eval("prison_eventDtl_srno") %>'
                                                                    CommandName="image" />
                                                                <br />
                                                                <asp:Label ID="lblImgDesc" runat="server" Visible="false" Text='<%# Bind("prison_eventDtl_Description") %>'></asp:Label>
                                                                <asp:Label ID="lblEvntId" runat="server" Visible="false" Text='<%# Bind("prison_event_id") %>'></asp:Label>
                                                                <asp:Label ID="lblImgSrno" runat="server" Visible="false" Text='<%# Bind("prison_eventDtl_srno") %>'></asp:Label>
                                                                <asp:Label ID="lblImgYn" runat="server" Visible="false" Text='<%# Bind("prison_eventDtl_activeYN") %>'></asp:Label>
                                                                &nbsp; &nbsp;
                                                            </td>
                                                        </tr>
                                                    </table>
                                                </ItemTemplate>
                                            </asp:DataList>
                                        </ContentTemplate>
                                        <%-- <Triggers>
                                             <asp:AsyncPostBackTrigger ControlID="dlEvnt" EventName="ItemCommand"  />
                                             </Triggers>--%>
                                    </asp:UpdatePanel>
                                </td>
                            </tr>
                            <tr>
                                <td colspan="1" style="font-weight: bold; color: #5C5C5C">
                                    Date and Venue:
                                </td>
                                <td colspan="1">
                                    <asp:Label ID="lblEvntDate" runat="server" Text='<%# Eval("prison_event_date") %>'
                                        Visible="false"></asp:Label>
                                </td>
                                <td colspan="2">
                                    <asp:Label ID="lblEvntVenue" runat="server" Text='<%# Eval("prison_event_venue") %>'
                                        Visible="false"></asp:Label></td>
                            </tr>
                            <%--   <tr>
                        <td colspan="4">
                        <asp:Label ID="lblEvntDate" runat="server" Text='<%# Eval("prison_event_date") %>'
                                    Visible="false"></asp:Label>
                        </td>
                        </tr>
                        <tr>
                        <td colspan="4">
                        <asp:Label ID="lblEvntVenue" runat="server" Text='<%# Eval("prison_event_venue") %>'
                                    Visible="false"></asp:Label>
                        </td>
                        </tr>--%>
                            <tr>
                                <td colspan="4" style="font: 15px Tahoma, Verdana, sans-serif; padding-top: 4px;
                                    border: solid 1px #99A866;">
                                    <div style="height: 181px; overflow: auto;">
                                        <asp:Label ID="lblEvntDesc" runat="server" Text='<%# Eval("prison_event_description") %>'></asp:Label></div>
                                </td>
                            </tr>
                        </table>
                    </div>
                </div>
            </div>
            &nbsp;
            <p>
            </p>
            <div class="clear">
            </div>
        </div>
        <div id="footer">
            <p>
                &copy; 2009 all rights reserved.</p>
            <p>
                Developed &amp; Maintained by Goa Electronics Limited
            </p>
            <p>
                www.goaelectronics.co.in</p>
        </div>
    </form>
</body>
</html>

the part i want refreshed is

<tr>
<td colspan="4" style="width: 540px">
<asp:UpdatePanel ID="updpEvnt" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<%--OnSelectedIndexChanged="selectedIndexChanged" "--%>
<aspataList ID="dlEvnt" runat="server" HorizontalAlign="Left" RepeatDirection="Horizontal"
BorderColor="#99A866" RepeatColumns="3" GridLines="Both" OnItemCommand="imageSelect"
DataKeyField="prison_eventDtl_srno" Visible="false">
<ItemTemplate>
<table width="100%" onmouseover="dg_changeBackColor(this, true);" onmouseout="dg_changeBackColor(this, false);">
<tr>
<td align="center" colspan="4">
<asp:ImageButton ID="imgDlEvnt" runat="server" Height="51px" Width="66px" AlternateText="Photo"
BorderColor="Silver" BorderStyle="Solid" ImageAlign="Middle" ImageUrl='<%# "~/ASHX/ImageHandler.ashx?queryType=dl_image&__KEY="+ Eval("prison_event_id")+"&__imgId="+Eval("prison_eventDtl_srno") %>'
CommandName="image" />
<br />
<asp:Label ID="lblImgDesc" runat="server" Visible="false" Text='<%# Bind("prison_eventDtl_Description") %>'></asp:Label>
<asp:Label ID="lblEvntId" runat="server" Visible="false" Text='<%# Bind("prison_event_id") %>'></asp:Label>
<asp:Label ID="lblImgSrno" runat="server" Visible="false" Text='<%# Bind("prison_eventDtl_srno") %>'></asp:Label>
<asp:Label ID="lblImgYn" runat="server" Visible="false" Text='<%# Bind("prison_eventDtl_activeYN") %>'></asp:Label>
&nbsp; &nbsp;
</td>
</tr>
</table>
</ItemTemplate>
</aspataList>
</ContentTemplate>
<%-- <Triggers>
<asp:AsyncPostBackTrigger ControlID="dlEvnt" EventName="ItemCommand" />
</Triggers>--%>
</asp:UpdatePanel>
</td>
</tr>

please tell me what to do....the whole page is getting refreshed

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