Topic: Link to new folder!

I have read the help text on the simple viewer site:
http://www.airtightinteractive.com/simp … omize.html

And i need the function To Customize XML Data Source! But i do not understand how to use it!
I have made the folder to a php string $myfolder and the xml file is the same : gallery.xml

Sorry for my bad english, hope you understands and know how to help me!