var chapter_list = new Array(
  ["Vol.01 Ch.000.1: two cursed swords","v01/c000.1"],
  ["Vol.01 Ch.000.2","v01/c000.2"],
  ["Vol.02 Ch.000.1","v02/c000.1"],
  ["Vol.02 Ch.000.2","v02/c000.2"],
  ["Vol.03 Ch.000.1","v03/c000.1"],
  ["Vol.03 Ch.000.2","v03/c000.2"],
  ["Vol.04 Ch.000.1","v04/c000.1"],
  ["Vol.04 Ch.000.2","v04/c000.2"],
  ["Vol.05 Ch.000.1","v05/c000.1"],
  ["Vol.05 Ch.000.2","v05/c000.2"],
  ["Vol.06 Ch.000.1","v06/c000.1"],
  ["Vol.06 Ch.000.2","v06/c000.2"],
  ["Vol.07 Ch.000.1","v07/c000.1"],
  ["Vol.07 Ch.000.2","v07/c000.2"],
  ["Vol.08 Ch.000","v08/c000"],
  ["Vol.09 Ch.000","v09/c000"],
  ["Vol.10 Ch.000","v10/c000"],
  ["Vol.11 Ch.000","v11/c000"],
  ["Vol.12 Ch.000","v12/c000"],
  ["Vol.13 Ch.000","v13/c000"],
  ["Vol.14 Ch.000","v14/c000"],
  ["Vol.15 Ch.000","v15/c000"],
  ["Vol.16 Ch.000","v16/c000"],
  ["Vol.17 Ch.000.1","v17/c000.1"],
  ["Vol.17 Ch.000.2","v17/c000.2"],
  ["Vol.18 Ch.000","v18/c000"],
  ["Vol.19 Ch.000","v19/c000"],
  ["Vol.20 Ch.078: Shouren's Past","v20/c078"],
  ["Vol.20 Ch.079: Alliance of the Human and Demon Realms","v20/c079"],
  ["Vol.20 Ch.080.1: Moving Forward!","v20/c080.1"],
  ["Vol.20 Ch.080.2: Moving Forward!","v20/c080.2"],
  ["Vol.21 Ch.081: Nymphs","v21/c081"],
  ["Vol.21 Ch.082.1","v21/c082.1"],
  ["Vol.21 Ch.082.2","v21/c082.2"],
  ["Vol.21 Ch.083","v21/c083"],
  ["Vol.22 Ch.001.1: Part 1","v22/c001.1"],
  ["Vol.22 Ch.001.2: Part 2","v22/c001.2"],
  ["Vol.22 Ch.001.3: Part 3","v22/c001.3"],
  ["Vol.23 Ch.001","v23/c001"],
  ["Vol.23 Ch.002","v23/c002"],
  ["Vol.23 Ch.003","v23/c003"],
  ["Vol.23 Ch.004","v23/c004"],
  ["Vol.23 Ch.005","v23/c005"],
  ["Vol.23 Ch.006","v23/c006"],
  ["Vol.24 Ch.001","v24/c001"]
);

var total_chapters = 45;

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;