var chapter_list = new Array(
  ["Vol.01 Ch.001: Case1: The Reunion","v01/c001"],
  ["Vol.01 Ch.001.5: Case1: The Reunion","v01/c001.5"],
  ["Vol.01 Ch.002: Case2: The Promise","v01/c002"],
  ["Vol.01 Ch.003: Case3: The Memory","v01/c003"],
  ["Vol.01 Ch.004: Case4: Flight","v01/c004"],
  ["Vol.01 Ch.005: 5-6","v01/c005"],
  ["Vol.02 Ch.007: An Old Enemy","v02/c007"],
  ["Vol.02 Ch.008: Ruthless","v02/c008"],
  ["Vol.02 Ch.009: Penalty","v02/c009"],
  ["Vol.02 Ch.010: Madness","v02/c010"],
  ["Vol.02 Ch.011: Affection","v02/c011"],
  ["Vol.02 Ch.012: Passion","v02/c012"],
  ["Vol.03 Ch.013: Choice","v03/c013"],
  ["Vol.03 Ch.014: Choice(2)","v03/c014"],
  ["Vol.03 Ch.015: I Ask A Soul","v03/c015"],
  ["Vol.03 Ch.016: Love and Hate","v03/c016"],
  ["Vol.03 Ch.017: Break In","v03/c017"],
  ["Vol.03 Ch.018: Push Forward","v03/c018"],
  ["Vol.03 Ch.019: Bloody Battle","v03/c019"],
  ["Vol.03 Ch.020: Great Battle","v03/c020"],
  ["Vol.03 Ch.021: Eternity","v03/c021"]
);

var total_chapters = 21;

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;