var chap_array = new Array(
    ["9 - Do You Want to Look",'9'],

    ["8 - Where Did This Tangerine-Colored Memory Come From",'8'],

    ["7 - Can It Become a Memory",'7'],

    ["6 - Lovey-Dovey",'6'],

    ["5 - Happy",'5'],

    ["4 - Should I Confess",'4'],

    ["3 - Why Do I Care So Much",'3'],

    ["2 - You Call This Gentle",'2'],

    ["1 - Don't Tell Me Beauty Should Be Punished",'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]);
    }
}