update progress control not working in asp.net

[Msberry]

I have defined an \[code\]<asp:UpdatePanel>\[/code\] with an \[code\]<asp:UpdateProgress>\[/code\] as\[code\] <asp:ScriptManager ID="sm1" runat="server"></asp:ScriptManager> <asp:UpdatePanel ID="update1" runat="server"> <ContentTemplate> <asp:Label id="lblresult" runat="server"></asp:Label><br /><br /> <asp:Button ID="btn1" runat="server" Text="Refresh" OnClick="btn1_Click" /> <br /> </ContentTemplate> </asp:UpdatePanel> <asp:UpdateProgress ID="up1" runat="server" AssociatedUpdatePanelID="update1"> <ProgressTemplate> <span style="color:green; font-style:italic;">Loading, please wait...</span> </ProgressTemplate> </asp:UpdateProgress> \[/code\]The button event is defined as\[code\]protected void btn1_Click(object sender, EventArgs e){ lblresult.Text = "<span style='color:red;'>"+ DateTime.Now.ToString() +"</span>";}\[/code\]However, I do not get the \[code\]Loading, please wait...\[/code\]