embedding php scripts

hi!
this is a little OT, but I think it’s of general interest.

I want to include() a php gallery script in my wordpress homepage. actually the script (gallerize) creates thumbnail and links to full images in a subdirectory, /gallery/ .

my problem is: when I include /gallery/index.php in my homepage template, it takes as a working directory the root of my website, not the /gallery subdir.

there is a way for including scripts, but making them work in their own directory?
I think I have to modify something in the following lines:
#Open the cwd and build a list of JPG files
$jpegs = array();
$directory = opendir(getcwd()) ;

could you please help me?
thank you.
ale.