private void chaptersComboBox__SelectedIndexChanged(object sender, EventArgs e)
{
if (manga_ == null)
{
return;
}
string chapter = chaptersComboBox_.Items[chaptersComboBox_.SelectedIndex].ToString();
pictureBox1_.Image = Properties.Resources.Loading;
centerImage();
pictureBox1_.Refresh();
manga_.ChangeToChapter(chapter);
pictureBox1_.Select();
}