how to update table inside div using update panel

<div id="MSGd" style="display: none" class="topline bottomline leftline rightline centered">  
<div class="bodytext" align="left">
  <table id="lst1" width="700"cellpadding="0" cellspacing="0" border="0">

    <tr>
        <td align="left" class="bottomline">
            <div class="bodytext">
                P.I.D
            </div>
        </td>
        <td align="left" class="bottomline">
            <asp:TextBox ID="txtpid" runat="server" MaxLength="20" Width="150"></asp:TextBox>
            <%--<asp:Button ID="btnpid" runat="server" Width="30" Text="pid" OnClick="btnpid_Click" bac CssClass="style=ba" />--%>
            <asp:ImageButton ID="btnpid" runat="server"  OnClick="btnpid_Click" ImageUrl="~/App_Themes/DISHA/Images/search-icon.gif" />
        </td>
                        <td align="left" class="bottomline">
                            <div class="bodytext">
                                Patient Name
                            </div>
                        </td>
                        <td align="left" class="bottomline">
                            <asp:TextBox ID="txtpatientname" runat="server" MaxLength="20" Width="150"></asp:TextBox><span
                                style="color: #ff0033">*</span>
                        </td>
                    </tr>

ds = BFB.fn_Get_PID(txtpid.Text);

if (ds.Tables[0].Rows.Count > 0)
{
    txtmobile.Text = ds.Tables[0].Rows[0]["MobileNo"].ToString();
    txtpatientname.Text = ds.Tables[0].Rows[0]["Fname"].ToString();
    txtguardiansname.Text = ds.Tables[0].Rows[0]["FatherName"].ToString();
    txtphone.Text = ds.Tables[0].Rows[0]["PhoneNo"].ToString();
    ddlsex.SelectedValue = ds.Tables[0].Rows[0]["sex"].ToString();
    txtday.Text = ds.Tables[0].Rows[0]["Age"].ToString();
}