public void setSelectedChapter(int chapterNumber, int bookNumber) {
		System.out.println(bookNumber+ " " + chapterNumber);
		chapterNumber = chapterNumber - 1;
		int i = 0;
		boolean wasFound = false;
		for(i = 0;i < selectedChapters.get(bookNumber).size();i++){
			if(selectedChapters.get(bookNumber).get(i).equals(chapterNumber)){
				wasFound = true;
				break;
			}
		}
		if(!wasFound){
			selectedChapters.get(bookNumber).add(chapterNumber);
		}
		else {
			selectedChapters.get(bookNumber).remove(i);
		}
	}