Adding unobtrusive progress bar to old-school file uploads

Question

You all know the new generation of fancy, mostly Flash-based file uploaders like SWFUpload that can show a progress bar while uploading - a great improvement especially for

Answer 1

You'll have to check the size of the part of the file wich is allready on the Server, then get it on the Client per Ajax where you can paint the progress bar. (Remember to check the size of the hole Data before, to calculate the percantage ;-) )