Ho una pagina con un iframe che con un image button assegno la pagina da aprire.
Vorrei poter creare un ProgressBar, che si attiva al caricamento della pagina e si chiude quando il caricamento è stato completato.
E' fattibile ? Posto il codice

Protected Sub CercaProdotto_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles CercaProdotto.Click
Dim frame02 As HtmlControl = CType(Me.FindControl("frame01"), HtmlControl)
frame02.Attributes("src") = "VariazioneAnagraficaProdotto.aspx"

End Sub


<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default5.aspx.vb" Inherits="Default5" EnableSessionState="True" %>

<!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 runat="server">
<title></title>
</head>
<body bgcolor="Lime">
<form id="formIframe" runat="server">
<div>

<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>

<asp:UpdatePanel ID="UpdatePanel4" runat="server">
<ContentTemplate>

<table style="border: 1px solid #000000; table-layout: fixed; width: 350px; background: transparent; border: 1px solid #000000; border-spacing: 5px; padding: 00px; top: 45px; left: 15px; height: 30px;">
<tr style="border-style: none; text-align: center;">
<td style="border-width: 0px; width: 35px; border-style: none">Anno</td>
<td><aspropDownList ID="AnnoSolare" runat="server"
Style="text-align:right; width: 55px; margin-left: 0px;" /></td>
<td style="border-width: 0px; width: 5px; border-style: none"></td>
<td style="border-width: 0px; width: 64px; border-style: none">Prodotto</td>
<td><asp:TextBox ID="NumeroProdotto" runat="server" Style="text-align:right; width: 60px;" TabIndex="1" Font-Size="9pt" Height="16px" /></td>
<td><asp:ImageButton ID="CercaProdotto" runat="server" ImageUrl="~/immagini/avanti.png" Width="16px" /></td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>

<asp:UpdateProgress ID="UpdateProgress1" runat="server" AssociatedUpdatePanelID="UpdatePanel1" DynamicLayout="False">
<ProgressTemplate>
<div id="IMGDIV" align="center" valign="middle" runat="server" style="position: absolute;left: 35%;top: 25%;visibility:visible;vertical-align:middle;border-style:inset;border-color:black;background-color:#c8d1d4;">
<asp:Image ID="Image1" runat="server" ImageUrl="25-1.gif" />
</div>
</ProgressTemplate>
</asp:UpdateProgress>


<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>

<iframe id="frame01" runat="server" src="default.aspx" width="1200px" height="800px" frameborder="0" enableviewstate="True"> </iframe>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>