آقا من وقتی این پروژه را run میکنم این Erro را میده
Error 2 Unable to create type 'Ajax:UpdatePanelAnimationExtender'. Could not load file or assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified. D:\C\E\CSharp\WebSite Sample\Final Forum Project\SiteAdmin\EnterForumsCategories.aspx 65
