var chapter_list = new Array(
  ["Vol.01 Ch.001: Welcome to the Digimon Net Game","v01/c001"],
  ["Vol.01 Ch.002: Black-Winged Knight","v01/c002"],
  ["Vol.01 Ch.003: Greymon vs Peckmon","v01/c003"],
  ["Vol.01 Ch.004: Commantments of Terror","v01/c004"],
  ["Vol.01 Ch.005: Yuu and Gaomon!","v01/c005"],
  ["Vol.01 Ch.006: i-Land!","v01/c006"],
  ["Vol.02 Ch.007: vs Cannonbeemon","v02/c007"],
  ["Vol.02 Ch.008","v02/c008"],
  ["Vol.02 Ch.009","v02/c009"],
  ["Vol.02 Ch.010: The Girl Norun","v02/c010"],
  ["Vol.02 Ch.011: Pichimon's Secret","v02/c011"],
  ["Vol.02 Ch.012: The City of Light, Light City!!","v02/c012"],
  ["Vol.03 Ch.013","v03/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.04 Ch.019","v04/c019"],
  ["Vol.04 Ch.020","v04/c020"],
  ["Vol.04 Ch.021","v04/c021"],
  ["Vol.04 Ch.022: The Demon Lord Barbamon!","v04/c022"],
  ["Vol.04 Ch.023: Neo/","v04/c023"],
  ["Vol.04 Ch.024: A Fight Against the Future!","v04/c024"],
  ["Vol.04 Ch.025: Digital World!","v04/c025"]
);

var total_chapters = 25;

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;