var chap_array = new Array(
["A Princess and A Bum 2",'a-princess-and-a-bum-2'],
["A Princess and A Bum 1",'a-princess-and-a-bum-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]);
}