Hi Ram,

It sounds like you are moving from Windows to Web application development, so welcome aboard.  It's a great place to be.  Unfortunately, there are many things you cannot do in the web environment that you can do in a Win forms app.  Drag and drop files is one of those limitations.  I'm assuming you're talking about dragging files from the Windows Explorer or My Computer and dropping them onto the file listbox.  To be completely accurate, this actually can be done, but only by writing something like a custom ActiveX control that runs inside your browser.  This isn't usually an option, since most corporate firewalls filter out the ActiveX controls from web traffic.

If you're goal is to provide file upload capabilities, you may want to check out http://swfupload.org/.  The control is designed for uploading images, but it would be fairly easy to modify it to support generic file uploads.

HTH,

Don Worthley