var chapter_list = new Array(
  ["Vol.01 Ch.000: Extra","v01/c000"],
  ["Vol.01 Ch.001","v01/c001"],
  ["Vol.01 Ch.002","v01/c002"],
  ["Vol.01 Ch.003","v01/c003"],
  ["Vol.01 Ch.004.1","v01/c004.1"],
  ["Vol.01 Ch.004.2","v01/c004.2"],
  ["Vol.02 Ch.001","v02/c001"],
  ["Vol.02 Ch.002","v02/c002"],
  ["Vol.02 Ch.003","v02/c003"],
  ["Vol.02 Ch.004","v02/c004"],
  ["Vol.02 Ch.005","v02/c005"],
  ["Vol.02 Ch.006","v02/c006"],
  ["Vol.03 Ch.001","v03/c001"],
  ["Vol.03 Ch.002","v03/c002"],
  ["Vol.03 Ch.003","v03/c003"],
  ["Vol.03 Ch.004","v03/c004"],
  ["Vol.03 Ch.005","v03/c005"],
  ["Vol.03 Ch.006","v03/c006"],
  ["Vol.03 Ch.007","v03/c007"],
  ["Vol.03 Ch.008","v03/c008"],
  ["Vol.04 Ch.001","v04/c001"],
  ["Vol.04 Ch.002","v04/c002"],
  ["Vol.04 Ch.003","v04/c003"],
  ["Vol.04 Ch.004","v04/c004"],
  ["Vol.04 Ch.005","v04/c005"],
  ["Vol.04 Ch.006","v04/c006"],
  ["Vol.04 Ch.007","v04/c007"],
  ["Vol.04 Ch.008","v04/c008"],
  ["Vol.04 Ch.009","v04/c009"],
  ["Vol.04 Ch.010","v04/c010"],
  ["Vol.05 Ch.001","v05/c001"],
  ["Vol.05 Ch.002","v05/c002"],
  ["Vol.05 Ch.003","v05/c003"],
  ["Vol.05 Ch.004","v05/c004"],
  ["Vol.05 Ch.005","v05/c005"],
  ["Vol.05 Ch.006","v05/c006"],
  ["Vol.05 Ch.007","v05/c007"],
  ["Vol.05 Ch.008","v05/c008"],
  ["Vol.05 Ch.009","v05/c009"],
  ["Vol.05 Ch.010","v05/c010"],
  ["Vol.06 Ch.001","v06/c001"],
  ["Vol.06 Ch.002","v06/c002"],
  ["Vol.06 Ch.003","v06/c003"],
  ["Vol.06 Ch.004","v06/c004"],
  ["Vol.06 Ch.005","v06/c005"],
  ["Vol.06 Ch.006","v06/c006"],
  ["Vol.06 Ch.007","v06/c007"],
  ["Vol.06 Ch.008","v06/c008"],
  ["Vol.07 Ch.001","v07/c001"],
  ["Vol.07 Ch.002","v07/c002"],
  ["Vol.07 Ch.003","v07/c003"],
  ["Vol.07 Ch.004","v07/c004"],
  ["Vol.07 Ch.005","v07/c005"],
  ["Vol.08 Ch.001","v08/c001"],
  ["Vol.08 Ch.002","v08/c002"],
  ["Vol.09 Ch.001","v09/c001"],
  ["Vol.09 Ch.002","v09/c002"],
  ["Vol.09 Ch.003","v09/c003"],
  ["Vol.09 Ch.004","v09/c004"],
  ["Vol.09 Ch.005","v09/c005"],
  ["Vol.09 Ch.006","v09/c006"],
  ["Vol.09 Ch.007","v09/c007"],
  ["Vol.09 Ch.008","v09/c008"],
  ["Vol.09 Ch.009","v09/c009"],
  ["Vol.09 Ch.010","v09/c010"],
  ["Vol.09 Ch.011","v09/c011"],
  ["Vol.09 Ch.012","v09/c012"],
  ["Vol.09 Ch.013","v09/c013"],
  ["Vol.09 Ch.014","v09/c014"],
  ["Vol.09 Ch.015","v09/c015"],
  ["Vol.09 Ch.016","v09/c016"],
  ["Vol.09 Ch.017","v09/c017"],
  ["Vol.09 Ch.018","v09/c018"],
  ["Vol.09 Ch.019","v09/c019"],
  ["Vol.10 Ch.001","v10/c001"]
);

var total_chapters = 75;

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;