ajax question

whban

i have a asp.net web form.
i using asp.net ajax update panel.

But i have a question, is it the web control object must include inside the update panel, so only we can put c??

eg:

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

        <asp:Button ID="Button1" runat="Server" Text="Refresh"  />
        <br />
        <br />
        <asp:UpdatePanel ID="UpdatePanel1" runat="Server" UpdateMode="conditional">
        <ContentTemplate>
            Label within the Update Panel Refreshed at:
            <aspabel ID="Label1" runat="server"></aspabel>
        
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger C EventName="Click" />
        </Triggers>
      
        </asp:UpdatePanel>


This example is show us able to put button1 outside the updatepanel, but why in my project i fail to do it..


my 2nd question is, i also have a update panel, can i inside include many web control...example maybe more then 20 textbox and label...will it effect the performence?
because i had a 3 dropdownlist and many more textbox, but 1 of it every time i click on it...after select, my page will freeze a short while...but other 2 dropdownlist no problem, any idea??

对不起，用华语打有点难解释....