The the basename or dirname functions to easily access file and directory names using php. This is a good way to create css classes from file names.
files, strings
$full_path = '/swf/myflashfile.swf';
$file = basename($full_path); // $file is "myflashfile.swf'"
$dir = dirname($full_path); // $dir is "/swf/myflashfile.swf'"