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 unescape(document.cookie.substring(c_start,c_end));
          }
        }
      return "";
    }    
    
    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 var 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;
    }

    function eraseCookie(name) {
      createCookie(name,"",-1);
    }