var chap_array = new Array(
    ["12 - Melody of Going Towards the Future",'12'],

    ["11 - A-Desire that Wants to be Told",'11'],

    ["10 - Each Desire",'10'],

    ["9 - Confession",'9'],

    ["8 - Let's Go to Jungle Kingdom",'8'],

    ["7 - A Passing Encounter",'7'],

    ["6 - Execute Project M!",'6'],

    ["5 - Heart Days",'5'],

    ["4 - Ohanami Panic!",'4'],

    ["3 - Makiko's Situation",'3'],

    ["2 - This Is Sakura",'2'],

    ["1 - A New Season",'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]);
    }
}