ajax error

i have this error in web config and it is due to ajax 1.0

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.

what have i to do??
how can i add ajax 3.5??

 

Hi,
What have you done so far? i.e., added the correct version to your root /bin/ etc.
All the best,
Mark

 

ok with that..
i think i have fixed that..
thank you!!

 

...Good job ;-)