function setActiveStyleSheet(newSheetName) {
  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") == newSheetName) a.disabled = false;
    }
  }
}

function createCookie( name, value) {
    var date = new Date();
    date.setTime(date.getTime()+31536000000);
    var expires = "; expires="+date.toGMTString();
  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;
}
function getBrowserWidth() {
	if (window.innerWidth) {return window.innerWidth;}
	else if (document.documentElement && document.documentElement.clientWidth != 0) {return document.documentElement.clientWidth;}
	else if (document.body) {return document.body.clientWidth;}
	return 0;
}

function getStyleSheetFromResolution() {
	var theWidth = getBrowserWidth();	
	var theStyleSheet = "viaduc";
	if (theWidth <= 800){theStyleSheet = "viaduc800";}	
	return theStyleSheet;	
}

function loadStyleSheet() {
  var cookieStyleSheetValue = readCookie("theStyleSheet");
  var theStyleSheet = cookieStyleSheetValue ? cookieStyleSheetValue : getStyleSheetFromResolution();
  if (theStyleSheet != actualStyleSheet ) {
	  setActiveStyleSheet(theStyleSheet);
	  actualStyleSheet = theStyleSheet;
	  createCookie("theStyleSheet", theStyleSheet);	 
   }
}

window.onunload = function(e) {
  	var cookieStyleSheetValue = getStyleSheetFromResolution();
  	createCookie("theStyleSheet", cookieStyleSheetValue);
};
window.onresize = function(e) {
  var cookieStyleSheetValue = getStyleSheetFromResolution();
  setActiveStyleSheet(cookieStyleSheetValue);
  createCookie("theStyleSheet", cookieStyleSheetValue);
};

var actualStyleSheet = "viaduc";
loadStyleSheet();