// JScript 文件

/* Style Switcher by Paul Sowden, see A List Apart:  
http://www.alistapart.com/articles/alternate/ */ 

//1、设置动态有效的 css链接
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; 
    } 
  } 
} 

//2、返回有效的 css链接
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; 
} 

//创建 cookies 存入 css链接的 title名称
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;
} 

//
//页面初始化

//加载页面完成后触发
window.onload = function(e) { 
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title); 
} 

//关闭或刷新页面后触发
window.onunload = function(e) { 
  var title = getActiveStyleSheet(); 
  createCookie("style", title, 365); 
} 

//设置当前页面 css链接
var cookie = readCookie("style"); 
var title = cookie ? cookie : getPreferredStyleSheet(); 


if (title != undefined && title.length != 0)
{}
else
{title="blue";}
setActiveStyleSheet(title); 
//document.writeln("<div id=\"textsize\">Text Size: <a href=\"#\" onclick=\"setActiveStyleSheet 
//(’Small Text’); return false;\" title=\"Switch to Small Text Size\" id=\"text-small\">S</a><a  
//href=\"#\" onclick=\"setActiveStyleSheet(’Medium Text’); return false;\" title=\"Switch to  
//Medium Text Size\" id=\"text-medium\">M</a><a href=\"#\" onclick=\"setActiveStyleSheet(’Large  
//Text’); return false;\" title=\"Switch to Large Text Size\" id=\"text-large\">L</a></div>");