$source_file = 'U:\\sites\\put\\upload\\2003_image5_76.jpg';
I think there might be some confusion. PHP is a server side language. It cannot see anything on a clients computer that is not sent through the browser. the $source_file would have to be a file that is already on the server in a tmp dir or something. PHP alone cannot read a file off of a remote computer.
for more info on handling file uploads