var ns = navigator.appName == 'Netscape';
 var ie = !ns;
 var version = parseInt(navigator.appVersion);
 var ie3= ie && version < 4;

 var NS4 = (document.layers) ? 1 : 0;
 var IE4 = (document.all) ? 1 : 0;

var isIE4;
var isNav4;
var isNav6;

// Determine which browser is used

function setbrowser() {
	if (navigator.appVersion.charAt(0) == "4") {
		if (navigator.appName.indexOf("Explorer") >= 0) {
			isIE4 = true;
		}
		else {
			isNav4 = true;
		}
	}
	else if (navigator.appVersion.charAt(0) > "4") {
		isNav6 = true;
	}
}

setbrowser();

function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}

var CSAg = window.navigator.userAgent; 
var CSBVers = parseInt(CSAg.charAt(CSAg.indexOf("/")+1),10);


function IsIE() { return window.navigator.userAgent.indexOf("MSIE") > 0;}
function CSIEStyl(s) { return document.all.tags("div")[s].style; }
function CSNSStyl(s) { return CSFindElement(s,0); }


function CSFindElement(n,ly) { if (CSBVers < 4) return document[n];
	var curDoc = ly ? ly.document : document; var elem = curDoc[n];
	if (!elem) { for (var i=0;i<curDoc.layers.length;i++) {
		elem = CSFindElement(n,curDoc.layers[i]); if (elem) return elem; }}
	return elem;
}

e_CurrentChapter = "";
e_CurrentBook = "";

function eSwitchImage(imageObject, imageAction) {
	var img = null;
	if (document.images) {    
    	if (!IsIE()) img = CSFindElement(imageObject[0],0);
		else img = document.images[imageObject[0]];
		
		if (img) {
			if(imageAction == 'on') {
				img.src = imageObject[2];
			} else {
				img.src = imageObject[1];
			} 
		}                          
	}	                    
}


function eSetImage(imageObject) {
	var img = null;
	if (document.images) {    
		if (!IsIE()) img = CSFindElement(imageObject[0],0);
		else img = document.images[imageObject[0]];
		     
		if (img) {
			img.src = imageObject[1];
		}
	}  
}

 
       var current_popup     = "";
       var current_root      = "";
       var current_secondary = "";
 
       function enter_submenu(n,root) {
			eSwitchImage(root,'on');
			current_root = root;

             var layer_id = n;
             ae_showLayer(n);
             current_popup=n;
       }
                 
       function leave_submenu() {
       		 eSwitchImage(current_root,'off');
             if(current_popup != ""){
                   var layer_id = current_popup;
                    ae_hideLayer(layer_id);
             }
        }

function ae_showLayer(layerName){
	if (isNav4) {
		n_layer = document.layers[layerName];
	}
	else if (isIE4) {
		n_layer = document.all(layerName).style;
	}
	else if (isNav6) {
		n_layer = document.getElementById(layerName).style;
	}
	
		n_layer.visibility="visible";
}

function ae_hideLayer(layerName){
	n_layer = null;
	if (isNav4) {
		n_layer = document.layers[layerName];
	}
	else if (isIE4) {
		n_layer = document.all(layerName).style;
	}
	else if (isNav6) {
		n_layer = document.getElementById(layerName).style;
	}
	
	if(n_layer != null) {
		n_layer.visibility="hidden";
    }
}