KCallback.net

AJAX
AJAX (Asynchronous JavaScript And XML) enable your web applications to increase interactivity, speed and usability.

ASP.NET Standard controls & 3rd Party controls  
KCallback.net can AJAX enable standard ASP.NET controls and 3rd party controls. 

Save State 
You can save the state of all the form controls during callback request by setting the SaveState property to true.

Callback Result
Return callback result to a client-side function instead of rendering.

Callback Error
Return callback error to a client-side function for exception handling.

Override Output
Override the callback contents both on the server-side and client-side.

Loading Display
Display an HTML block while processing the callback request.

Disable Controls During Callback
KCallback.net can automatically disable selected controls during callback  

Enable Caching
Cache callback arguments and results on the client-side to improve performance.

MultiArgument
You can pass multiple arguments into the Callback event handler and process them on the server-side.

Auto Callback
Initiate callbacks automatically at specified intervals in milliseconds.

User Control
You can insert the KCallback.net control into a user control. So that you are able to run two instances of the same user control on the same page.

Client-Side API
KCallback.net support client side function to handle the result and error for the callback response from the server.

Server-Side API
Process callback request in the Callback event handler.

Before and After execute client side event handler 
This allows you to alter/cancel the callback before and after execute client side event.

XHTML Compliance
XHTML 1.0 Transitional compliant.