Here Mudassar Ahmed Khan has explained how to display (show) AJAX Control Toolkit ModalPopupExtender Modal Popup after validation of ASP.Net validators (such as RequiredFieldValidator) is successful in ASP.Net.

Here Mudassar Ahmed Khan has explained how to solve the problem of ASP.Net AJAX Control Toolkit loading too many script resources using the ASP.Net AJAX Control Toolkit Bundles feature.
Loading scripts for all ASP.Net AJAX Control Toolkit controls, increases page size and also slows down loading of page.
Hence ASP.Net AJAX Control Toolkit has introduced a new feature called Bundles that allows to specify which controls are being used in the application and ASP.Net AJAX Control Toolkit will load scripts only for those controls and not all.

Here Mudassar Ahmed Khan has explained with example, how to upload multiple files and images without Page PostBack, Refresh or Reload in ASP.Net using C# and VB.Net.

The ASP.Net AJAX Control Toolkit AjaxFileUpload control allows user to upload multiple files and images without page PostBack, Refresh or Reload.

Here Mudassar Ahmed Khan has explained with example, how to use the AJAX Control Toolkit AjaxFileUpload control in ASP.Net using C# and VB.Net.
The ASP.Net AJAX Control Toolkit AjaxFileUpload control allows user to upload multiple file with Drag and Drop and Progress bar functionality.

Drag and Drop functionality is supported only in browsers that allow upload of files using Drag and Drop.