var chap_array = new Array(
    ["17 - The Next Is",'17'],

    ["16 - One Victory",'16'],

    ["15 - The Conclusion",'15'],

    ["14 - Turnaround",'14'],

    ["13 - One More Point",'13'],

    ["12 - Challenge",'12'],

    ["11 - The Beginning of Summer",'11'],

    ["10 - End of Spring",'10'],

    ["9 - Steadily",'9'],

    ["8 - Amazing Pitcher 2",'8'],

    ["7 - Amazing Pitcher 1",'7'],

    ["6 - An Amazing Pitcher",'6'],

    ["5 - Conditions for Being a Pitcher",'5'],

    ["4 - First Run",'4'],

    ["3 - Play!",'3'],

    ["2 - Catcher Duty",'2'],

    ["1 - The True Ace",'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]);
    }
}