//global variables----------------------------------------------------

var layerRef="null",layerStyleRef="null",styleSwitch="null";
var currChap=0;
var sourceFile='';

function init(){
        if (navigator.appName == "Netscape") {
                layerStyleRef="layer.";
                layerRef="document.layers";
                styleSwitch="";
}	else {
                layerStyleRef="layer.style.";
                layerRef="document.all";
                styleSwitch=".style";
}}

function showLayer(layerName) {
        eval(layerRef+'["'+layerName+'"]'+styleSwitch+'.visibility="visible"');
}
        
function hideLayer(layerName) {
        eval(layerRef+'["'+layerName+'"]'+styleSwitch+'.visibility="hidden"');
}