How can I link to pages in a 2 level popup index/selection tree with java script?

Question

I can do a single level popup index using the java script below (#1) and link the selections to pages but to change to a  2 level popup index selection tree as below (#2) I can't seem to figure out how to link to pages. Any help greatly appreciated. Thanks
1
var itemIndex = app.popUpMenu("INTRODUCTION", "ALPHABET", "GRAMMAR", "NUMBERS", "DATES & TIME", "GETTING TO KNOW PEOPLE", "PHRASES FOR LEARNING", "DIRECTIONS & TRANSPORTATION", "DESCRIBING THE TRAIL", "DO'S & DON'TS", "EQUIPMENT", "FOOD", "INTRODUCING A VILLAGE", "CULTURE AND ETHNIC GROUPS", "HANDICRAFTS", "TEMPLES & MONKS", "AGRICULTURE", "ANIMAL HUSBANDRY", "SCHOOL & EDUCATION", "LEADING A TREK", "NATIONAL PROTECTED AREAS", "IDENTIFYING WILDLIFE", "PLANTS & FORESTS", "BOATS", "CAVES", "HEALTH AND SAFETY")
switch (itemIndex) {
case "INTRODUCTION":
this.pageNum = 1
break
case "ALPHABET":
this.pageNum = 2
break
case "GRAMMAR":
this.pageNum = 5
break
case "NUMBERS":
this.pageNum = 30
break
case "DATES & TIME":
this.pageNum = 35
break
case "GETTING TO KNOW PEOPLE":
this.pageNum = 42
break
case "PHRASES FOR LEARNING":
this.pageNum = 56
break
case "DIRECTIONS & TRANSPORTATION":
this.pageNum = 59
break
case "DESCRIBING THE TRAIL":
this.pageNum = 63
break
case "DO'S & DON'TS":
this.pageNum = 68
break
case "EQUIPMENT":
this.pageNum = 74
break
case "FOOD":
this.pageNum = 83
break
case "INTRODUCING A VILLAGE":
this.pageNum = 96
break
case "CULTURE AND ETHNIC GROUPS":
this.pageNum = 105
break
case "HANDICRAFTS":
this.pageNum = 120
break
case "TEMPLES & MONKS":
this.pageNum = 126
break
case "AGRICULTURE":
this.pageNum = 131
break
case "ANIMAL HUSBANDRY":
this.pageNum = 140
break
case "SCHOOL & EDUCATION":
this.pageNum = 145
break
case "LEADING A TREK":
this.pageNum = 151
break
case "NATIONAL PROTECTED AREAS":
this.pageNum = 155
break
case "IDENTIFYING WILDLIFE":
this.pageNum = 161
break
case "PLANTS & FORESTS":
this.pageNum = 169
break
case "BOATS":
this.pageNum = 175
break
case "CAVES":
this.pageNum = 178
break
case "HEALTH AND SAFETY":
this.pageNum = 182
break
2
var aINTRODUCTION = ["INTRODUCTION", "How to Use This Book", "Format"];
var aALPHABET = ["ALPHABET", "Vowel Sounds", "Consonant Sounds"];
var itemIndex = app.popUpMenu(aINTRODUCTION, aALPHABET);
Thanks.

Answer 1

Thanks. I've got it now. I was mistakenly renaming itemIndex to each section...Introduction, Alphabet