function showSelection(S, L, C, R) {
  	var on = C+'On';
	var off = C+'Off';
	var theLink = R+"_"+L;
	var theSelection = R+"_"+S;
	var currentLink = this[R+"_L"];
	var currentSelection = this[R+"_S"];
	if (currentLink != theLink || currentLink == null) {
		document.getElementById(theLink).className=on;
		if (currentLink != null) {
			document.getElementById(currentLink).className=off;
		}
		this[R+"_L"] = theLink;
	}
	if (currentSelection != theSelection || currentSelection == null) {		
		document.getElementById(theSelection).className="displayOn";
		if (currentSelection != null) {
			document.getElementById(currentSelection).className="displayOff";
		}
		this[R+"_S"] = theSelection;		
	}
}