// expand / collapse layers:
function expandCollapse() {
	for (var i=0; i<expandCollapse.arguments.length; i++) {
		var element = document.getElementById(expandCollapse.arguments[i]);
		element.style.display = (element.style.display == "none") ? "block" : "none";
	}
}

// change a CSS class:
function changeClass(elementID, className){
	document.getElementById(elementID).className = className ;
}