var chapter_list = new Array(
  ["Vol.01 Ch.001: In Love With Loving","v01/c001"],
  ["Vol.01 Ch.002: Member duty","v01/c002"],
  ["Vol.01 Ch.003","v01/c003"],
  ["Vol.01 Ch.004: The Stairway To Adulthood","v01/c004"],
  ["Vol.01 Ch.005: Sweet Kiss","v01/c005"],
  ["Vol.01 Ch.006: Camp!","v01/c006"],
  ["Vol.02 Ch.007: My Soulmate..?","v02/c007"],
  ["Vol.02 Ch.008","v02/c008"],
  ["Vol.02 Ch.009","v02/c009"],
  ["Vol.02 Ch.010: Amusement Park!!","v02/c010"],
  ["Vol.02 Ch.011: Competition","v02/c011"],
  ["Vol.02 Ch.012: Male Member","v02/c012"],
  ["Vol.02 Ch.013: Love Initiation","v02/c013"],
  ["Vol.02 Ch.014","v02/c014"],
  ["Vol.03 Ch.015: That Loving Feeling","v03/c015"],
  ["Vol.03 Ch.016: My Place","v03/c016"],
  ["Vol.03 Ch.017: Aquarium","v03/c017"],
  ["Vol.03 Ch.018: I Want To Know","v03/c018"],
  ["Vol.03 Ch.019: I Really Do Want To Know","v03/c019"],
  ["Vol.03 Ch.020: Brand New World","v03/c020"]
);

var total_chapters = 20;

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;