var chapter_list = new Array(
  ["Vol.01 Ch.001","v01/c001"],
  ["Vol.01 Ch.002","v01/c002"],
  ["Vol.01 Ch.003","v01/c003"],
  ["Vol.01 Ch.004","v01/c004"],
  ["Vol.02 Ch.005","v02/c005"],
  ["Vol.02 Ch.006","v02/c006"],
  ["Vol.02 Ch.007","v02/c007"],
  ["Vol.02 Ch.008","v02/c008"],
  ["Vol.02 Ch.009","v02/c009"],
  ["Vol.03 Ch.010","v03/c010"],
  ["Vol.03 Ch.011","v03/c011"],
  ["Vol.03 Ch.012","v03/c012"],
  ["Vol.03 Ch.013","v03/c013"],
  ["Vol.03 Ch.014","v03/c014"],
  ["Vol.04 Ch.015","v04/c015"],
  ["Vol.04 Ch.016","v04/c016"],
  ["Vol.04 Ch.017","v04/c017"],
  ["Vol.04 Ch.018","v04/c018"],
  ["Vol.04 Ch.019","v04/c019"],
  ["Vol.04 Ch.020","v04/c020"],
  ["Vol.05 Ch.021","v05/c021"],
  ["Vol.05 Ch.022","v05/c022"],
  ["Vol.05 Ch.023","v05/c023"],
  ["Vol.05 Ch.024","v05/c024"],
  ["Vol.05 Ch.025","v05/c025"],
  ["Vol.05 Ch.026","v05/c026"],
  ["Vol.06 Ch.004","v06/c004"],
  ["Vol.06 Ch.005","v06/c005"],
  ["Vol.06 Ch.006","v06/c006"],
  ["Vol.06 Ch.027","v06/c027"],
  ["Vol.06 Ch.028","v06/c028"],
  ["Vol.06 Ch.029","v06/c029"],
  ["Vol.07 Ch.030.1","v07/c030.1"],
  ["Vol.07 Ch.030.2","v07/c030.2"],
  ["Vol.07 Ch.031.1","v07/c031.1"],
  ["Vol.07 Ch.031.2","v07/c031.2"],
  ["Vol.07 Ch.032","v07/c032"],
  ["Vol.07 Ch.033","v07/c033"],
  ["Vol.07 Ch.034","v07/c034"],
  ["Vol.08 Ch.003","v08/c003"],
  ["Vol.08 Ch.004","v08/c004"],
  ["Vol.08 Ch.005","v08/c005"],
  ["Vol.08 Ch.006","v08/c006"],
  ["Vol.08 Ch.035","v08/c035"],
  ["Vol.08 Ch.036","v08/c036"],
  ["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: Swan Lake (special chapter)","v09/c006"],
  ["Vol.10 Ch.001","v10/c001"],
  ["Vol.10 Ch.002","v10/c002"],
  ["Vol.10 Ch.003","v10/c003"],
  ["Vol.10 Ch.004","v10/c004"],
  ["Vol.11 Ch.001","v11/c001"],
  ["Vol.11 Ch.002","v11/c002"],
  ["Vol.11 Ch.003","v11/c003"],
  ["Vol.11 Ch.004","v11/c004"],
  ["Vol.11 Ch.005","v11/c005"],
  ["Vol.11 Ch.006","v11/c006"],
  ["Vol.12 Ch.001","v12/c001"],
  ["Vol.12 Ch.002","v12/c002"],
  ["Vol.12 Ch.002.5","v12/c002.5"],
  ["Vol.12 Ch.003","v12/c003"],
  ["Vol.13 Ch.001.1","v13/c001.1"],
  ["Vol.13 Ch.002.1","v13/c002.1"],
  ["Vol.14 Ch.001","v14/c001"],
  ["Vol.14 Ch.002","v14/c002"],
  ["Vol.14 Ch.003","v14/c003"],
  ["Vol.14 Ch.004","v14/c004"],
  ["Vol.14 Ch.005","v14/c005"],
  ["Vol.14 Ch.006","v14/c006"]
);

var total_chapters = 73;

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;