Your web page seems to be offline at this time. Embedding into a web page is not your only option.
I built an add-in to a program built for KDE, called Marble, which is heavily reliant upon check boxes in order to display only certain chosen points of interest. (or all POIs, if chosen)
The file which links up all of your KML files inside of Marble is called a DGML file, you can use my DGML file as a template if it will help. KDE Marble comes standard with an OpenStreetMap layer, which is what I built on top of.