Hi,
In your local machine you are installed AJAX Beta2, so you are able to work on AJAX functionality,
but coming to your server, how can you run AJAX functionality without installation,
either you should install the AJAX Beta2 in your server
OR
install neccessary AJAX dll's in the GAC of the server
AJAX Beta2/Beta1 is not a part of .Net Framework,
Pradeep Kumar Bura
To make more interactive and sportive please check this as a answer if above information is helpful to you.