var current_page = 1;

function str_pad_left(s, length, c)
{
  while (s.length < length)
    s = c + s;
  
  return s;
}

function images_goto_page(page)
{
  if (page < 1) page = 1;
  if (page > page_count) page = page_count;
  
  document.getElementById("page" + current_page.toString()).style.textDecoration = "none";
  
  for (i = 1; i <= 4; i++)
  {
    var filename = str_pad_left(((page - 1) * 4 + i).toString(), 3, "0")
    var path1 = images_folder + "thumb_" + filename + ".jpg";
    var path2 = images_folder + filename + ".jpg";
    document.getElementById("i" + i.toString()).src = path1;
    document.getElementById("a" + i.toString()).href = path2; 
  }
  
  current_page = page;
  
  document.getElementById("page" + current_page.toString()).style.textDecoration = "underline";
}