var chapter_list = new Array(
  ["Vol.01 Ch.001: Crushing Love I","v01/c001"],
  ["Vol.01 Ch.002: Crushing Love II","v01/c002"],
  ["Vol.01 Ch.003: Crushing Love III","v01/c003"],
  ["Vol.01 Ch.004: Love Life","v01/c004"],
  ["Vol.01 Ch.005: Purity and Tyranny of Love","v01/c005"],
  ["Vol.01 Ch.006: Love of a Tyrant King","v01/c006"],
  ["Vol.01 Ch.007: My Throbbing Heart","v01/c007"],
  ["Vol.01 Ch.008: Love Love Me + Afterthoughts","v01/c008"]
);

var total_chapters = 8;

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;