JavaScript操作cookie

以下操作cookie在Firefox和Safari中测试成功，在IE中失败（读取、获取，改写，设置）。

经过反复测试，发现把http://127.0.0.1改为http://localhost之后，IE中也可以正常运行。

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 ""
     }

     function setCookie(c_name, value, expiredays) {
         var exdate = new Date();
         exdate.setDate(exdate.getDate() + expiredays);
         document.cookie = c_name + "=" + value + ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString()) + ";path=/";
         ;
     }

     function checkCookie() {
         master_headertop_narrow_show = getCookie('master_headertop_narrow_show')
         alert(master_headertop_narrow_show); //////
         if (master_headertop_narrow_show != null && master_headertop_narrow_show != "") {
             if (master_headertop_narrow_show == 'true') {
                 var master_headertop = document.getElementById('master_headertop');
                 if (master_headertop)
                     master_headertop.style.display = 'none';
                 var master_headertop_narrow = document.getElementById('master_headertop_narrow');
                 if (master_headertop_narrow)
                     master_headertop_narrow.style.display = 'block';

             }
         }
     }