parser error in asp.net?

i developed a web application it is working fine in local server. when i uploaded the site in online when i click on some of the buttons i am getting this error. I am using master page, but i am not place the scriptmanager in master page,i place the scriptmanager tag in every page. It is working fine in local server but it is giving error in online. please can u help me. Thank you

Parser Error
Description: An error occurred during the parsing of a resource required to
service this request. Please review the following specific parse error det开发者_开发问答ails
and modify your source file appropriately.

Parser Error Message: Unknown server tag 'asp:ScriptManager'.

Source Error:

Line 9:  <asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
Line 10: 
Line 11:     <asp:ScriptManager ID="ScriptManager1" runat="server">
Line 12:     </asp:ScriptManager>
Line 13:          <asp:UpdatePanel id="UpdatePanel2" runat="server" UpdateMode="Conditional">

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In first place you should compare your local web.config with the production web.config. It may be possible that you have missed one or more configuration items related to ajax.

Here you have a reference about how to configure an ajax application:

http://www.asp.net/ajax/documentation/live/ConfiguringASPNETAJAX.aspx

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Make sure the online site is set to use the right version of the .net framework. probably 3.5