// JavaScript Document
function addChapter() {
	
	var tmp = $("#chapterValues").val();
	
//	var combo = $("#combochapters");
	var selectedChapter = $("#combochapters").val();
	
	if(selectedChapter==0) {
		alert("Please select a chapter from a book.");	

	} else if(("," + tmp).indexOf("," + selectedChapter + ",")>-1) {   //== check if chapter is already added
		alert("This chapter has already been added.");
		
	} else {
		tmp +=  selectedChapter + ",";
		$("#chapterValues").val(tmp);
		outputChapters();
	}
	
}

function deleteChapter(chapterId) {
	var tmp = $("#chapterValues").val();
	
	var list = tmp.split(",");
	
	var newList = new Array();
	
	for(var i=0; i<list.length; i++) {
		if(list[i].toString()!=chapterId.toString()) 
			newList.push(list[i]);
	}
	
	$("#chapterValues").val(newList.join(","));

	outputChapters();
	
}

function outputChapters() {
	
	var combo = document.getElementById("combochapters");
	
	var options = combo.options;
	
	var tmp = $("#chapterValues").val();
	
	var html = "";
	
	for(var i=0; i<options.length; i++) {
		if( ("," + tmp).indexOf("," + options[i].value + ",")>-1) {
			html += ' <a href="Javascript:deleteChapter(' + options[i].value + ')">Delete</a> ';
			html += options[i].text
			html += '<br/>';
		}
	}
	
	$("#chaptersOutput").html(html);
	
}