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: The Police I.D.","v02/c008"],
  ["Vol.02 Ch.009: The Difference Between Truth and Lies","v02/c009"],
  ["Vol.02 Ch.010: Shattered to Pieces!?","v02/c010"],
  ["Vol.02 Ch.011: The Unforgivable Crime","v02/c011"],
  ["Vol.02 Ch.012","v02/c012"],
  ["Vol.02 Ch.013","v02/c013"],
  ["Vol.03 Ch.014","v03/c014"],
  ["Vol.03 Ch.015","v03/c015"],
  ["Vol.03 Ch.016","v03/c016"],
  ["Vol.03 Ch.017","v03/c017"],
  ["Vol.03 Ch.018","v03/c018"],
  ["Vol.03 Ch.019","v03/c019"],
  ["Vol.03 Ch.020","v03/c020"],
  ["Vol.03 Ch.021: Bar-B-Que","v03/c021"],
  ["Vol.03 Ch.022: Deep-Sea Fish","v03/c022"],
  ["Vol.04 Ch.023: Ikefukuro","v04/c023"],
  ["Vol.04 Ch.024: Blackboard","v04/c024"]
);

var total_chapters = 24;

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;