UltimateCallback is an ASP.NET server control to provide AJAX callback functionality in your web applications. It allows you to make web pages more responsive by exchanging data with the server behind the scenes. Every time the user initiates a callback request UltimateCallback control refreshes only its own contents instead of reloading the entire web page as in the case of a regular postback to server. Some of the key features are: * AJAX - AJAX (Asynchronous JavaScript And XML) * Drag-Drop * Callback Result * Callback Error * Loading Display * Enable Caching * Save State * Auto Callback * Override Output * Down Level Browser Support * Client-Side API * Server-Side API