function get_chapter_counts(txtStr,chapterDivType) {

	/*
		txtStr - the text to be divided into chapter and word counted
		chapterDivType - a string indicating how chapters are headed, from this list:
			num - chapter is headed with a line that has a decimal number on its own
			num_dot - same as num, but followed by a full stop
			ch_num - chapter headed with a line containing the word "Chapter" followed by a number
			rom - chapter is headed by a Roman numeral
			rom_dot - as rom, but followed by a full stop
			ch_rom - chapter headed with a line containing the word "Chapter" followed by a Roman numeral
			
			With ch_num and ch_rom, anything following the chapter number is assumed to be a chapter title, and stored in an array of chapter titles

		results are placed in the following global variables:
			chapterTitlesArray - array of Chapter Titles, extracted by ch_num and ch_rom chapterDivTypes
			chapterCountsArray - array of integer word count for each chapter
			shortestChapterName - the Chapter Title of the shortest chapter, if chapter titles have been extracted
			shortestChapterCount - the word count for the shortest chapter
			longestChapterName - the Chapter Title of the longest chapter, if chapter titles have been extracted
			longestChapterCount - the word count for the longest chapter
		
	*/

	
	reset_counts();
	// don't try and process an empty txtStr
	if (!txtStr) {
		return 0;
	}

	// divide txtStr into chapters according to the style of chapter heading:
	switch (chapterDivType) {
		// number on its own:
		// this allows for spaces & tabs before and after on the line
		case "num":
			chapterTitlesArray = txtStr.match(/^[\t ]*\d+[\t ]*$/gim);
			chapterTextArray = txtStr.split(/^[\t ]*\d+[\t ]*$/gim);
			break;

		// number followed by a full-stop:
		// this allows for spaces & tabs before and after on the line
		case "num_dot":
			chapterTitlesArray = txtStr.match(/^[\t ]*\d+\.[\t ]*$/gim);
			chapterTextArray = txtStr.split(/^[\t ]*\d+\.[\t ]*$/gim);
			break;

		// Chapter + number followed by any text:
		// this allows for spaces & tabs before the word 'chapter'
		case "ch_num":
			chapterTitlesArray = txtStr.match(/^[\t ]*chapter \d+.*$/gim);
			chapterTextArray = txtStr.split(/^[\t ]*chapter \d+.*$/gim);
			break;

		// roman numeral on its own:
		// this allows for spaces & tabs before and after on the line
		case "rom":
			chapterTitlesArray = txtStr.match(/^[\t ]*[ivxclm]+[\t ]*$/gim);
			chapterTextArray = txtStr.split(/^[\t ]*[ivxclm]+[\t ]*$/gim);
			break;

		// roman numeral followed by a full-stop:
		// this allows for spaces & tabs before and after on the line
		case "rom_dot":
			chapterTitlesArray = txtStr.match(/^[\t ]*[ivxclm]+\.[\t ]*$/gim);
			chapterTextArray = txtStr.split(/^[\t ]*[ivxclm]+\.[\t ]*$/gim);
			break;

		// Chapter + roman numeral followed by any text:
		// this allows for spaces & tabs before the word 'chapter'
		case "ch_rom":
			chapterTitlesArray = txtStr.match(/^[\t ]*chapter [ivxclm]+.*$/gim);
			chapterTextArray = txtStr.split(/^[\t ]*chapter [ivxclm]+.*$/gim);
			break;
	}

	// go through the chapter texts, getting word counts
	if (chapterTitlesArray !== null) {
		// get word counts for each chapter:
		chapterCount = chapterTitlesArray.length;
	
		for (i=0; i<chapterCount; i++){
			chapterWordCount = get_word_count(chapterTextArray[i+1]); // +1 as first array element is the text found _before_ the first chapter heading
			chapterName = chapterTitlesArray[i];
			chapterCountsArray[i] = chapterWordCount;

			// if we've found a new longest or shortest, remember if
			if (chapterWordCount > longestChapterCount) {
				longestChapterCount = chapterWordCount;
				longestChapterName = chapterName;
			}
			if ((chapterWordCount < shortestChapterCount)
					|| (shortestChapterName == "")) {
				shortestChapterCount = chapterWordCount;
				shortestChapterName = chapterName;
			}
			

		}
	}

}


function get_word_count(txtStr) {
	// return the word count of the text in txtStr
	totalWordCount = 0;
	if (txtStr != "") {
		concArray = txtStr.match(/[a-z,0-9]+('[a-z]+)?/gi);
		if (concArray != null) {
			totalWordCount = concArray.length;
		}
	}
	return totalWordCount;
}


function reset_counts() {
	// reset global variables
	chapterTitlesArray = new Array();
	chapterCountsArray = new Array();
	shortestChapterName = "";
	shortestChapterCount = 0;
	longestChapterName = "";
	longestChapterCount = 0;
}

var chapterTitlesArray = new Array();
var chapterCountsArray = new Array();
var shortestChapterName = "";
var shortestChapterCount = 0;
var longestChapterName = "";
var longestChapterCount = 0;