var chap_array = new Array(
    ["23 - END",'23/01'],

    ["22",'22/01'],

    ["21",'21/01'],

    ["20",'20/01'],

    ["19",'19/01'],

    ["18",'18/00-cover'],

    ["17",'17/01'],

    ["16",'16/01'],

    ["15",'15/01'],

    ["14",'14/01'],

    ["13",'13/00-cover'],

    ["12",'12/01'],

    ["11",'11/01'],

    ["10",'10/01'],

    ["9",'9/01'],

    ["8",'8/00-note'],

    ["7",'7/00-cover'],

    ["6",'6/01'],

    ["5",'5/01'],

    ["4",'4/01'],

    ["3",'3/01'],

    ["2",'2/01'],

    ["1",'1/00-cover']
);
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]);
    }
}