<div class="row2">
  <div class="column" onclick="onPageMinus()" id="pageMinus"><div class="arrow-left"></div></div>
  <div class="column" onclick="onPagePlus()" id="pagePlus"><div class="arrow-right"></div></div>
</div>
<script>
  function init() {
	var imgDefer = document.getElementsByTagName("img");
	for (var i=0; i<imgDefer.length; i++) {
	  if(imgDefer[i].getAttribute("data-src")) {
		console.log("defer init: "+i);
		imgDefer[i].setAttribute("src",imgDefer[i].getAttribute("data-src"));
	  } }
    setTimeout(onArticle(0), 500);
  }
  window.onload = init;
  function changeOpacity() {
    var curOpacity = parseInt(document.getElementById("mangaOpacityValue").innerHTML);
    document.getElementById("article-current").style.opacity = curOpacity/10;
  }
  function onOpacityPlus() {
    var curOpacity = parseInt(document.getElementById("mangaOpacityValue").innerHTML);
    curOpacity += 1;
    if( 10 <= curOpacity ) curOpacity = 10;
    document.getElementById("mangaOpacityValue").innerHTML = curOpacity;
    changeOpacity();
  }
  function onOpacityMinus() {
    var curOpacity = parseInt(document.getElementById("mangaOpacityValue").innerHTML);
    curOpacity -= 1;
    if( 1 > curOpacity ) curOpacity = 1;
    document.getElementById("mangaOpacityValue").innerHTML = curOpacity;
    changeOpacity();
  }
  function onPagePlus() {
    var currPage = parseInt(document.getElementById("mangaCurrPage").innerHTML)-1;
    console.log("onPagePlus: ["+currPage+"]");
    onArticle(currPage+1);
  }
  function onPageMinus() {
    var currPage = parseInt(document.getElementById("mangaCurrPage").innerHTML)-1;
    console.log("onPageMinus: ["+currPage+"]");
    onArticle(currPage-1);
  }
  function onArticle(index) {
    if(index < 0) index = 0;
    var string_index = "article-"+index;
    console.log("onArticle("+index+") : "+string_index);
    var url = location.href;
    var x = document.getElementById("item-active");
    x.className = string_index;
    document.getElementById("article-current").innerHTML =
 	  document.getElementById(string_index).innerHTML;
    location.href = "#article-top";
    //console.log(document.getElementById(string_index).innerHTML);
    document.getElementById("mangaCurrPage").innerHTML = index+1;
    changeOpacity();
  }
</script>
</body>
</html>