var chap_array = new Array(
    ["55 - Zamami",'55'],

    ["54 - Crossroads",'54'],

    ["53 - Sin",'53'],

    ["52 - Sacrifice",'52'],

    ["51 - Ceremony",'51'],

    ["50 - Combat",'50'],

    ["49 - Duel",'49'],

    ["48 - A Journey for Two",'48'],

    ["47 - Mar",'47'],

    ["46 - Homesick",'46'],

    ["45 - Peru",'45'],

    ["44 - Sprouting",'44'],

    ["43 - Turnaround",'43'],

    ["42 - Engagement",'42'],

    ["41 - Cave Diving",'41'],

    ["40 - Lies",'40'],

    ["39 - Jealosy",'39'],

    ["38 - Rift",'38'],

    ["37 - Keystone",'37'],

    ["36 - Resonance",'36'],

    ["35 - Visit",'35'],

    ["34 - Mio",'34'],

    ["33 - Nagisa",'33'],

    ["32 - Aftershock",'32'],

    ["31 - After the Typhoon",'31'],

    ["30 - Ambush",'30'],

    ["29 - Torrential Storms",'29'],

    ["28 - Doubts",'28'],

    ["27 - Grand Opening",'27'],

    ["26 - Debut",'26'],

    ["25 - Machiko",'25'],

    ["24 - Hawaii",'24'],

    ["23 - Navigation",'23'],

    ["22 - Professor",'22'],

    ["21 - The Promise",'21'],

    ["20 - Pile Up",'20'],

    ["19 - Secret",'19'],

    ["18 - Whale Watching",'18'],

    ["17 - Decompression Sickness",'17'],

    ["16 - Ascend",'16'],

    ["15 - Escape",'15'],

    ["14 - Ruins",'14'],

    ["13",'13'],

    ["12 - Confession",'12'],

    ["11 - Buddy",'11'],

    ["10 - Naha Night",'10'],

    ["9 - The Real Reason",'9'],

    ["8 - Going to Tokyo",'8'],

    ["7 - Return to Tokyo",'7'],

    ["6 - Sea Corner",'6'],

    ["5 - Back Painting",'5'],

    ["4 - After Diving",'4'],

    ["3 - Diving Experience",'3'],

    ["2 - Miyara Three Sisters",'2'],

    ["1 - To The Ocean of Okinawa",'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]);
    }
}