Set AutoUpload="false" to let users review their selected files before
uploading. A separate upload button allows them to start when ready.
Drag & drop files here, or paste from clipboard
<au:AjaxFileUpload ID="Uploader1" runat="server"
AllowMultiple="true"
AutoUpload="false"
ButtonText="Select Files"
ShowProgress="true" />
<button onclick="AjaxUploader.getInstance('Uploader1').startUpload()">
Start Upload
</button>