you could just use the above code, comment out the line that starts with $error.="The File... and add this line right below it:
PHP Code:
unlink($folder.$file_name[$i]);
It would look something like this:
PHP Code:
// Check if the file already exists on the server..
} Elseif(file_exists($folder.$file_name[$i])) {
// $error.= "The file: ".$_FILES['file']['name'][$i]." exists on this server, please rename your file.<br />Your file(s) were <b>not</b> uploaded.<br />";
unlink($folder.$file_name[$i]);