Create a web page where the Upload Control, UploadManager Control and ProgressPanel Control work together. You can set the UploadControl.AutoPostback property to true, which causes the upload process to begin as soon as files are selected. The ProgressPanel will appear (with default styling) as soon as the upload begins.

Multiple Upload controls can be used on a single form to allow users to upload more than one file at a time. The 'Upload' button is a standard Button control that initiates the upload operation when the form is submitted, all without a PostBack.

You can incorporate custom input fields into a file upload form. Because the upload process is occurring asynchronously, all form field values are available within events raised by the UploadManager control.

The OpenFileDialog control offers the same uploading behavior found in the Upload control, but without any intrinsic visual properties. To use this control, you set the ClientTriggerElement and ClientTriggerEvent properties to determine which control and event will cause the file dialog to open.