// call set_landmark(mark) within the html_code section of a page
// it appends the mark parameter to all links with the ".markable" class

function set_landmark(mark) {
	
	if(mark != undefined){
		$$(".markable").each(function(link) {
			link.writeAttribute('href', link.readAttribute('href') + "?mark=" + mark);
		});
	}
}