哪里可以获得“最新的”ASP .NET预览DLL和脚本

I have been trying to download the ASP .NET AJAX Futures but I can only see old versions of the DLL via sample tutorials from other websites. I need the DLL to use the Drag and Drop feature according to these tutorials. I know the tutorial is already old but I was wondering if they are still supported? (Microsoft.Web.Preview.dll, PreviewDragDrop.js) I have been trying to download the ASP .NET AJA