var isActive = ""
var isActiveSubKat = 0
var started = false;
var listener = true;
var currentChapter = 0;
function showSub(which,deaktivieren) {
	if (isActive!="") {
		document.getElementById(isActive).style.visibility="hidden";
		//document.getElementById("navigation").style.height = "20px";
	}
	if (which!="") {	
		document.getElementById(which).style.visibility="visible";
		//document.getElementById("navigation").style.height = "200px";
	}
	else {
	    listener = true;
	}
	
	isActive = which;
	if (which=="") MM_swapImgRestore();
	
}