javascript设置和获取cookie的通用方法

//获取cookie  
function getCookieValue(cookieName)  
{  
   var cookieValue = document.cookie;  
   var cookieStartAt = cookieValue.indexOf(""+cookieName+"=");  
   if(cookieStartAt==-1)  
   {  
       cookieStartAt = cookieValue.indexOf(cookieName+"=");  
   }  
   if(cookieStartAt==-1)  
   {  
       cookieValue = null;  
   }  
   else  
   {  
       cookieStartAt = cookieValue.indexOf("=",cookieStartAt)+1;  
       cookieEndAt = cookieValue.indexOf(";",cookieStartAt);  
       if(cookieEndAt==-1)  
       {  
           cookieEndAt = cookieValue.length;  
       }  
       cookieValue = unescape(cookieValue.substring(cookieStartAt,cookieEndAt));//解码latin-1  
   }  
   return cookieValue;  
} 

http://blog.csdn.net/taozi165/article/details/6553544