WHY does file upload work only on local server

Tricky image uploading. Everything works fine on my local server. But on the remote server the scripts wants to find the local file path on the remote server?! (E.g. I have a file input field and enter the local file path of the image to be uploaded, e.g. c:/images/image1.jpg. When I submit the form the script replies : "... Warning: Unable to open 'c:\images\image1.jpg for reading: No such file or directory in /u/web/quarti/system_htm/aw.php3 on line ..." (which is the path of my remote server, where my php-script is) So how can I make the server (apache/unix) read the file in the local source-directory and then upload it (which works without any problems when I run the script on my local server pointing to another directory containing an image-file). Does anybody know the TRICK? Thanks alot Helmut