function setCookie(key, value, expires)
            {
                var t = new Date();
                t.setMinutes(t.getMinutes() + expires);

                var s = key + "=" + encodeURIComponent(value) +
                        ";expires=" + t.toUTCString();

                document.cookie = s;
                
            }
  
 function getCookie(c_name)   
 {   
  if (document.cookie.length>0)   
    {   
    c_start=document.cookie.indexOf(c_name + "=");   
    if (c_start!=-1)   
      {    
      c_start=c_start + c_name.length+1 ;   
       c_end=document.cookie.indexOf(";",c_start);   
      if (c_end==-1) c_end=document.cookie.length;   
      return document.cookie.substring(c_start,c_end);   
      }    
    }   
   return null;
  }

  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();   
  }