var chapter_list = new Array(
  ["Vol.01 Ch.001.1: Kotaro & Teppai","v01/c001.1"],
  ["Vol.01 Ch.001.2: [continuation] \ 2: Resurrection of X!","v01/c001.2"],
  ["Vol.01 Ch.002.2: [continuation]","v01/c002.2"],
  ["Vol.01 Ch.003.1: Battler at the Junkyard, Fou Lafini and Je T'aime","v01/c003.1"],
  ["Vol.01 Ch.003.2: [continuation]","v01/c003.2"],
  ["Vol.01 Ch.003.3: [continuation]","v01/c003.3"],
  ["Vol.02 Ch.001: Phoenix!  The Holy Book of Death","v02/c001"],
  ["Vol.02 Ch.002: The Route to Base","v02/c002"],
  ["Vol.02 Ch.003: Pirates of the Desert","v02/c003"],
  ["Vol.02 Ch.004: The Secret of Machine Empire","v02/c004"],
  ["Vol.03 Ch.001.1: Oasis's Mirage","v03/c001.1"],
  ["Vol.03 Ch.001.2: [continuation] \ 2: Color of Heart","v03/c001.2"],
  ["Vol.03 Ch.002.2: [continuation] \ 3: The Four Spirit Knights","v03/c002.2"],
  ["Vol.03 Ch.003.2: [continuation] \ 4: Maria, the Girl at the Grave","v03/c003.2"],
  ["Vol.03 Ch.004.2: [continuation]","v03/c004.2"]
);

var total_chapters = 15;

for (var i = 0; i < chapter_list.length; i++) {
  document.getElementById('top_chapter_list').options[i] = new Option(chapter_list[i][0], chapter_list[i][1]);
  document.getElementById('bottom_chapter_list').options[i] = new Option(chapter_list[i][0], chapter_list[i][1]);
}
document.getElementById('top_chapter_list').value=current_chapter;
document.getElementById('bottom_chapter_list').value=current_chapter;
var current_chapter_index = document.getElementById('top_chapter_list').selectedIndex;