/**** Browser detection ****/

var ns=0;
var ie =0;
if(document.getElementById && (parseInt(navigator.appVersion) >= 5 || navigator.appVersion.indexOf["MSIE 5"] != -1)){
	ns=6; ie=6;
}
else if (document.all) { 
  ns=0; ie=1;
}
else if (document.layers) { 
  ns=1; ie=0;
}

function browserDetect() {
	ns4 = (document.layers)&&(navigator.appName=="Netscape")&&(parseInt(navigator.appVersion)==4) ? 'ns4' : false;
	ie4 = (document.all)&&(navigator.appName.indexOf("Microsoft") > -1)&&(parseInt(navigator.appVersion)==4) ? 'ie4' : false;
	ie5 = (document.getElementById)&&(navigator.appName.indexOf("Microsoft") > -1) ? 'ie5' : false;
	ns6 = (document.getElementById)&&(navigator.appName=="Netscape")&&(parseInt(navigator.appVersion)>4) ? 'ns6' : false;
	op5 = (document.getElementById)&&(navigator.appName=="Opera")&&(parseInt(navigator.appVersion)>4) ? 'op5' : false;
	return (ns4 || ie5 || ie4 || ns6 || op5);
}

var browser = browserDetect();

function myDOM(id) {
	if (browser == 'ns4') {return document.layers[id];}
	if (browser == 'ie4') {return eval('document.all.'+ id);}
	if (browser == 'ie5') {return document.getElementById(id);}
	if (browser == 'ns6') {return document.getElementById(id);}
	return false;
}

function getStyle(id) {
    //alert(id);
    if(browser == 'ns4') {
      return myDOM(id);
    }
	if((browser == 'ie4') || (browser == 'ie5') || (browser == 'ns6')) {
      return myDOM(id).style;
    }
}	


/**** show/hide layers ****/
function showHideLayer(newLayer, command) {
  getStyle(newLayer).visibility = command;
  //setTimeout("getStyle('" + newLayer + "').visibility = 'hidden'", 5000);
}

function showHideAll() {
  myDOM("nav_off").src = "images/nav/nav_off.gif";
  getStyle("layerHideTrigger").visibility = "hidden";
}

function swapImg(oldImg, newImg) {
    //getStyle("layerHideTrigger").visibility = "visible";
    myDOM(oldImg).src = "images/" + newImg;
	//eval(newImg + ".src")
}


function setCookie(name, value) {
  document.cookie = name + "=" + value;
  //alert(document.cookie);
}

function getAlpNums(area) {
  var startIdx = document.cookie.indexOf(area);
  var endIdx = document.cookie.indexOf(";", startIdx);
  var newStr;
  
  // check to see if chapter cookie has been set
  if(document.cookie.indexOf(area) != -1) {
    if(endIdx != -1) {
	  newStr = document.cookie.slice(startIdx, endIdx);
    } else {
	  newStr = document.cookie.slice(startIdx);
    }
  }
  return newStr.slice(newStr.indexOf("=")+1);
}

function getTitle(area) {
  var startIdx = document.cookie.indexOf(area);
  var endIdx = document.cookie.indexOf(";", startIdx);
  var newStr;
  
  // check to see if cookie has been set
  if(document.cookie.indexOf(area) != -1) {
    if(endIdx != -1) {
	  newStr = document.cookie.slice(startIdx, endIdx);
    } else {
	  newStr = document.cookie.slice(startIdx);
    }
  }
  
  if(area=="chapter") {
    return eval(area)[newStr.slice(newStr.indexOf("=")+1)];
  }

  if(area=="section") {
    return eval(area)[tranverseSection(newStr.slice(newStr.indexOf("=")+1))][0];
  }
}

function setChapter(curChapter) {
  setCookie("chapter", curChapter);
}

function getChapterNumber() {
  return getAlpNums("chapter");
}

function getChapterTitle() {
  return getTitle("chapter");
}

function tranverseSection(numOrAlp) {
  var executeFlag = true;
  var alps = new Array("A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z");
  
  for(var idx=0; idx<=alps.length; idx++) {
    // Check if it is an Alp. first
    if(alps[idx]==numOrAlp) {
      //alert(alps[idx] + "==" + numOrAlp);
  	  executeFlag=false;
	  //alert(eval(idx+1));
	  return eval(idx+1);
    }
  }

  if(executeFlag) {
    return alps[numOrAlp-1];
  }
}

function setSection(curSection) {
  setCookie("section", curSection);
}

function getSectionNumber() {
  return getAlpNums("section");
}

function getSectionTitle() {
  return getTitle("section");
}

function setFigure(curFigure) {
  setCookie("figure", curFigure);
}

function getFigureNumber() {
  return getAlpNums("figure");
}

function popupWin(loc, title, attribs) {
  window.open(loc, title, attribs);
}