Asp .Net: Ajax validator compilation error

Hi..
my application is on Ajax Enabled web site it is showing some Errors

Error 29 Could not load type 'System.Web.UI.Compatibility.CompareValidator' from assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. (E:\Inetpub\wwwroot\connexajax\web.config line 21) E:\Inetpub\wwwroot\coexajax\Default.aspx 7

like this it is showing some errors for validators

re: Asp .Net: Ajax validator compilation error

I Did some search online...
found this site

Guess that is some known issue with the ajax components.
Hope it works out for you too