var chap_array = new Array(
    ["17 - Destruction",'17'],

    ["16 - Pandora",'16'],

    ["15 - Conversation",'15'],

    ["14 - Boss",'14'],

    ["13 - No4",'13'],

    ["12 - Retrieve",'12'],

    ["11 - Monster",'11'],

    ["10 - Designer",'10'],

    ["9 - Alvas",'9'],

    ["8 - Notice",'8'],

    ["7 - Gamble",'7'],

    ["6 - Inference",'6'],

    ["5 - Controller",'5'],

    ["4 - Triangularity",'4'],

    ["3 - Targets",'3'],

    ["2 - Revenge",'2'],

    ["1 - Invasion",'1'],

    ["0 - Start",'0']
);
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]);
    }
}