Unrecognized namespace 'mvc'

Jul 3, 2012 at 7:52 PM

I did everything the manual said, but when I add this:

<mvc:ScriptManager runat="server">        <Scripts>            <mvc:ScriptReference Path="~/Scripts/jquery-1.2.6.js" />            <mvc:ScriptReference Path="~/Scripts/Sample.js"        EnableCrunching="true" ResourceAssembly="SampleWeb"             ResourceName="SampleWeb.Sample" ResourceTypeName="Sample" />         </Scripts>    </mvc:ScriptManager> 

I get: Recognized namespace 'mvc', that as if I were not recognizing the reference MvcScriptManager.

 

Why can this be happening?

 

thanks!