var chapter_list = new Array(
  ["Vol.01 Ch.001: Be My Baby","v01/c001"],
  ["Vol.01 Ch.002: Tandem","v01/c002"],
  ["Vol.01 Ch.003: Wolf Boy","v01/c003"],
  ["Vol.01 Ch.004: Graduation","v01/c004"],
  ["Vol.01 Ch.005: You're Under Arrest","v01/c005"],
  ["Vol.01 Ch.006: Lemon Innocent","v01/c006"],
  ["Vol.02 Ch.007: More Gently","v02/c007"],
  ["Vol.02 Ch.008: So Gloomy I Could Die","v02/c008"],
  ["Vol.02 Ch.009: Comic Strip","v02/c009"],
  ["Vol.02 Ch.010: From Her to Eternity","v02/c010"],
  ["Vol.02 Ch.011: [Side Story] Triangle House","v02/c011"]
);

var total_chapters = 11;

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;