a=getCookie("username3");
 c_start=document.cookie.indexOf("username3=");
 if(c_start == -1){
  $("#login_form").show();
     $("#logined").hide();
 }
 else{
  $("#login_form").hide();
     $("#logined").show();
     $("#ustr").html(a);
 }

//写入cookie到主域，设置过期时间为一年
    function SetCookie(name, value) {
        console.log(name, value)
        var str = name + "=" + escape(value) + ";domain=.cnblogs.com;path=/";
        var date = new Date();
        date.setTime(date.getTime() + 365 * 24 * 60 * 60 * 1000); //设置date为当前时间加一年

        str += ";expires=" + date.toGMTString();
        console.log(str)
        document.cookie = str;
    }

 //获得coolie 的值
function cookie(name){    
   var cookieArray=document.cookie.split("; "); //得到分割的cookie名值对    
   var cookie=new Object();    
   for (var i=0;i<cookieArray.length;i++){    
      var arr=cookieArray[i].split("=");       //将名和值分开    
      if(arr[0]==name)return unescape(arr[1]); //如果是指定的cookie，则返回它的值    
   } 
   return ""; 
} 

//删除cookie
function delCookie(name)
{
   document.cookie = name+"=;expires="+(new Date(0)).toGMTString();
}

//获取指定名称的cookie的值
function getCookie(objName){
    var arrStr = document.cookie.split("; ");
    for(var i = 0;i < arrStr.length;i ++){
        var temp = arrStr[i].split("=");
        if(temp[0] == objName) return unescape(temp[1]);
   } 
}

//添加cookie
function addCookie(objName,objValue,objHours){      
    var str = objName + "=" + escape(objValue);
    if(objHours > 0){                               //为时不设定过期时间，浏览器关闭时cookie自动消失
        var date = new Date();
        var ms = objHours*3600*1000;
        date.setTime(date.getTime() + ms);
        str += "; expires=" + date.toGMTString();
   }
   document.cookie = str;
}

//两个参数，一个是cookie的名子，一个是值
function SetCookie(name,value)
{
    var Days = 30; //此 cookie 将被保存 30 天
    var exp = new Date();    //new Date("December 31, 9998");
    exp.setTime(exp.getTime() + Days*24*60*60*1000);
    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}

//取cookies函数        
function getCookie(name)
{
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
    if(arr != null) return unescape(arr[2]); return null;
}

//删除cookie
function delCookie(name)
{
    var exp = new Date();
    exp.setTime(exp.getTime() - 1);
    var cval=getCookie(name);
    if(cval!=null) document.cookie= name + "="+cval+";expires="+exp.toGMTString();
}