var chapter_list = new Array(
  ["Vol.01 Ch.001: Is it true that first love won't ever be fulfilled","v01/c001"],
  ["Vol.01 Ch.002: Is it first come, first served when it comes to love?","v01/c002"],
  ["Vol.01 Ch.003: Is there only one answer?","v01/c003"],
  ["Vol.01 Ch.004: Can you stop loving someone?","v01/c004"],
  ["Vol.02 Ch.005: Can't I Be A Strong Girl?","v02/c005"],
  ["Vol.02 Ch.006: Is it silly to believe?","v02/c006"],
  ["Vol.02 Ch.007: Have you ever cried so much that your tears went dry?","v02/c007"],
  ["Vol.02 Ch.008: Was it a good thing for me to be in love with you?","v02/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;