how to browse folder using browse button from any location(from any drive) on server

Hi...i m new to .net...i m creating a asp.net web appliaction in which i need to select source file using browse button to select the Source location from where the files has to be copied from and destination file using browse button tos elect the destination location where the files has to be copied to .So pls tell me what should be the code for browse button to browse a folder for source and destination and copy the sorce foler files to destination folder(i want to copy only txt and excel files from source to destination folder) and i want user to see the progress how files are copying from source to destination and error also if thr is any error in copying.