function setActiveStyleSheet(title) {
  var i, a, main;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
      a.disabled = true;
      if(a.getAttribute("title") == title) a.disabled = false;
    }
  }
}

function getActiveStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return null;
}

function getPreferredStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       ) return a.getAttribute("title");
  }
  return null;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  current_css = ca;
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

window.onload = function(e) {
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);

function cssBtns(){
	var sFlag;
	var mFlag;
	var lFlag;

	if(current_css == "style=font2" || current_css == ""){
		sFlag="Off";
		mFlag="On";
		lFlag="Off";
	}else if(current_css == "style=font1"){
		sFlag="On";
		mFlag="Off";
		lFlag="Off";
	}else if(current_css == "style=font3"){
		sFlag="Off";
		mFlag="Off";
		lFlag="On";
	}

	var f_src = "<div id=\"fontSize\" class=\"medium\">";
	f_src += "文字サイズ　";
	f_src += " | <a href=\"#\" onclick=\"setActiveStyleSheet('font1');HeadSwap('font1click');\">";
	f_src += "<span id=\"fontSizeSmall\"><span class=\"fontSize" + sFlag + "\">小</span></span>";
	f_src += "</a>";
	f_src += " | <a href=\"#\" onclick=\"setActiveStyleSheet('font2');HeadSwap('font2click');\">";
	f_src += "<span id=\"fontSizeMiddle\"><span class=\"fontSize" + mFlag + "\">中</span></span>";
	f_src += "</a>";
	f_src += " | <a href=\"#\" onclick=\"setActiveStyleSheet('font3');HeadSwap('font3click');\">";
	f_src += "<span id=\"fontSizeLarge\"><span class=\"fontSize" + lFlag + "\">大</span></span>";
	f_src += "</a>";
	f_src += " |</div>";

	document.write(f_src);

}

function HeadSwap(whatSize) {
	var fs = document.getElementById("fontSizeSmall");
	var fm = document.getElementById("fontSizeMiddle");
	var fl = document.getElementById("fontSizeLarge");
	
	if(whatSize == "font1click"){
		fs.innerHTML = "<span class='fontSizeOn'>小</span>";
		fm.innerHTML = "<span class='fontSizeOff'>中</span>";
		fl.innerHTML = "<span class='fontSizeOff'>大</span>";
	}else if(whatSize == "font2click"){
		fs.innerHTML = "<span class='fontSizeOff'>小</span>";
		fm.innerHTML = "<span class='fontSizeOn'>中</span>";
		fl.innerHTML = "<span class='fontSizeOff'>大</span>";
	}else if(whatSize == "font3click"){
		fs.innerHTML = "<span class='fontSizeOff'>小</span>";
		fm.innerHTML = "<span class='fontSizeOff'>中</span>";
		fl.innerHTML = "<span class='fontSizeOn'>大</span>";
	}
	
}