<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<table class="tabla_1" width="900" align="center">
<tr>
<td class="style13">
<asp:Label ID="Label1" runat="server" Text="Buscar:"></asp:Label>
</td>
<td class="style14">
<asp:TextBox ID="txtBusqueda" runat="server" Width="250px"></asp:TextBox>
<asp:ImageButton ID="imgBuscar" ToolTip="Buscar" ImageAlign="AbsMiddle" ImageUrl="~/imagen/buscar.png"
runat="server" OnClick="imgBuscar_Click" ValidationGroup="1" />
</td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>
...
<asp:Panel runat="server" ID="pnlPersonas" Style="background-color: #ffffff; display: none">
<fieldset>
<legend>Resultados de la Busqueda</legend>
<table class="tabla_2" width="800" align="center">
<tr>
<td class="style3">
<asp:Label ID="Label3" runat="server" Text="Coincidencias: "></asp:Label>
</td>
<td class="style4">
<asp:Label ID="lblCantidad" runat="server" Text="..."></asp:Label>
</td>
<td align="right" class="style4">
<asp:ImageButton ID="imgClosePopup" runat="server" ImageAlign="AbsMiddle" ImageUrl="~/imagen/eliminar.png" />
</td>
</tr>
<tr>
<td align="center" colspan="3" valign="middle">
<asp:GridView ID="gvColegiados" runat="server" AllowPaging="True" CellPadding="3"
CellSpacing="2" ForeColor="#333333" AutoGenerateColumns="False" OnPageIndexChanging="gvColegiados_PageIndexChanging"
OnRowCommand="gvColegiados_RowCommand" Width="700px">
<FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<RowStyle BackColor="#EFF3FB" />
<Columns>
<asp:ButtonField ButtonType="Image" CommandName="Seleccionar" ImageUrl="~/imagen/aceptar.png" />
<asp:BoundField DataField="Cod_Colegiado" HeaderText="ID" />
<asp:BoundField DataField="Nombre" HeaderText="Nombre">
<ItemStyle HorizontalAlign="Left" />
</asp:BoundField>
<asp:BoundField DataField="Apellido" HeaderText="Apellido">
<ItemStyle HorizontalAlign="Left" />
</asp:BoundField>
<asp:BoundField DataField="DNI" HeaderText="DNI" />
<asp:BoundField DataField="Sexo" HeaderText="Sexo" />
</Columns>
<PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<AlternatingRowStyle BackColor="White" />
</asp:GridView>
</td>
</tr>
</table>
</fieldset>
</asp:Panel>
<asp:ModalPopupExtender ID="pnlPersonas_ModalPopupExtender" runat="server" DropShadow="True"
DynamicServicePath="" Enabled="True" TargetControlID="ImageButton1" PopupControlID="pnlPersonas"
BackgroundCssClass="fondoModalPopup" CancelControlID="imgClosePopup">
</asp:ModalPopupExtender>
<asp:ImageButton ID="ImageButton1" Style="display: none" runat="server" />