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(';');
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;
}

<!--親ウィンドウの値を表示　開始-->
function st() {
//	var str = location.search;
	var str = location.search.substr(1).split("&");
	if (str == "print") {
	var title = "print";
	setActiveStyleSheet(title);
	}else{
	var cookie = readCookie("style");
	var title = cookie ? cookie : getPreferredStyleSheet();
	setActiveStyleSheet(title);
	}
}

//イベントに処理を追加する(onloadの割り当て対策)
if (window.addEventListener) { //for W3C DOM
  window.addEventListener("load", st, false);
} else if (window.attachEvent) { //for IE
  window.attachEvent("onload", st);
} else  {
  window.onload = st;
}


function unst() {
var title = getActiveStyleSheet();
	if (title != "print") {
	createCookie("style", title, 365);
	}
}

//イベントに処理を追加する(onloadの割り当て対策)
if (window.addEventListener) { //for W3C DOM
  window.addEventListener("unload", unst, false);
} else if (window.attachEvent) { //for IE
  window.attachEvent("onunload", unst);
} else  {
  window.onunload = unst;
}

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