var chap_array = new Array(
["Adolf 11",'adolf-11'],
["Adolf 10",'adolf-10'],
["Adolf 9",'adolf-9'],
["Adolf 8",'adolf-8'],
["Adolf 7",'adolf-7'],
["Adolf 6",'adolf-6'],
["Adolf 5",'adolf-5'],
["Adolf 4",'adolf-4'],
["Adolf 3",'adolf-3'],
["Adolf 2",'adolf-2'],
["Adolf 1",'adolf-1']);

for (var i=0; i<chap_array.length; i++) {
document.getElementById('chapter_select').options[i] = new Option(chap_array[i][0],chap_array[i][1]);
}