js用iframe刷百度頁面報(bào)的exceptiion是什么意思??？

<div>

<iframe id = 'iframe1' height=500 width =500 src='http://www.baidu.com'>
</iframe>

</div>
<script>
var iframe1 = document.getElementById('iframe1')
interval = setInterval(function(){

    iframe1.setAttribute('src','http://www.baidu.com');
},5000);

</script>

報(bào)錯(cuò)信息：
Uncaught DOMException: Blocked a frame with origin "https://www.baidu.com" from accessing a cross-origin frame.

at HTMLDocument.t (https://ss1.bdstatic.com/5eN1bjq8AAUYm2zgoY3K/r/www/cache/static/protocol/https/global/js/all_async_search_44ab0b6.js:177:309)
at b3 (https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/js/lib/jquery-1.10.2_d88366fd.js:25:20852)
at Object.fireWith [as resolveWith] (https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/js/lib/jquery-1.10.2_d88366fd.js:25:21846)
at Function.ready (https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/js/lib/jquery-1.10.2_d88366fd.js:14:3703)
at HTMLDocument.bW (https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/js/lib/jquery-1.10.2_d88366fd.js:14:757)

t @ VM2899 all_async_search_44ab0b6.js:177
b3 @ VM2895 jquery-1.10.2_d88366fd.js:25
fireWith @ VM2895 jquery-1.10.2_d88366fd.js:25
ready @ VM2895 jquery-1.10.2_d88366fd.js:14
bW @ VM2895 jquery-1.10.2_d88366fd.js:14