var chap_array = new Array(
    ["16 - 20th Century Boys",'16'],

    ["15 - I'm Sorry",'15'],

    ["14 - There's No Way I'll Let It End",'14'],

    ["13 - Punch Out",'13'],

    ["12 - The Switch",'12'],

    ["11 - Goodbye Manjome",'11'],

    ["10 - The Remenant of a Demon",'10'],

    ["9 - Rules of the Game",'9'],

    ["8 - You Died Today",'8'],

    ["7 - Hiding Place",'7'],

    ["6 - Imitating the Imitation",'6'],

    ["5 - Ghost of the Future",'5'],

    ["4 - Origin of the Children",'4'],

    ["3 - Our Flag",'3'],

    ["2 - The Adult in the Dream",'2'],

    ["1 - Friend Dies",'1']
);
for (var i=0; i<chap_array.length; i++) {
    document.getElementById('id_chapter_1').options[i] = new Option(chap_array[i][0],chap_array[i][1]);
    if (document.getElementById('id_chapter_2')) {
        document.getElementById('id_chapter_2').options[i] = new Option(chap_array[i][0],chap_array[i][1]);
    }
}