ASP.Net web config problem

Hi guy i got problem on the web configure when upload to iis and it come out this error Server Error in '/myTT' Application
Configuration Error
Error line 31=<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/></assemblies></compilation>

Below is my web config code:

<?xml version="1.0"?>
<!-- 
    Note: As an alternative to hand editing this file you can use the 
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in 
    machine.config.comments usually located in 
    \Windows\Microsoft.Net\Framework\v2.x\Config 
-->
<configuration>
	<appSettings/>
	<connectionStrings>
  <add name="myTT_CS" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\TechServices.mdf;Integrated Security=True;User Instance=True"
   providerName="System.Data.SqlClient" />
 </connectionStrings>
	<system.web>
		<!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.

            Visual Basic options:
            Set strict="true" to disallow all data type conversions 
            where data loss can occur. 
            Set explicit="true" to force declaration of all variables.
        -->
		<compilation debug="true" strict="false" explicit="true">
			<assemblies>
				<add assembly="System.DirectoryServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
				<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/></assemblies></compilation>
		<pages>
			<namespaces>
				<clear/>
				<add namespace="System"/>
				<add namespace="System.Collections"/>
				<add namespace="System.Collections.Specialized"/>
				<add namespace="System.Configuration"/>
				<add namespace="System.Text"/>
				<add namespace="System.Text.RegularExpressions"/>
				<add namespace="System.Web"/>
				<add namespace="System.Web.Caching"/>
				<add namespace="System.Web.SessionState"/>
				<add namespace="System.Web.Security"/>
				<add namespace="System.Web.Profile"/>
				<add namespace="System.Web.UI"/>
				<add namespace="System.Web.UI.WebControls"/>
				<add namespace="System.Web.UI.WebControls.WebParts"/>
				<add namespace="System.Web.UI.HtmlControls"/>
			</namespaces>
		</pages>
		<!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
        -->
		<authentication mode="Windows"/>
		<!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
	</system.web>
</configuration>