clientHeight와 box의 offsetHeight로 초기의 vertical-middle값을 구한뒤,
scrollTop으로 scroll되는 값을 계산게 된다.
<![CDATA[<script type="text/javascript">
function test() {
var tbox = document.getElementById("box");
var lpos = parseInt(document.body.offsetWidth/2) - parseInt(tbox.offsetWidth/2) + "px
var tpos = parseInt(document.documentElement.clientHeight/2) +
parseInt(document.documentElement.scrollTop ) - parseInt(tbox.offsetHeight/2) + "px";
tbox.style.left = lpos + "px";
tbox.style.top = tpos + "px
return false;
}
</script>
<body>
<div id="box"></div>
<div style="margin:0; padding:0; border:none; background:none; float:none; clear:none; z-index:0"></div>
<script type="text/javascript" src="https://tistory1.daumcdn.net/tistory_admin/userblog/userblog-95a3f4c5b5122612c9f21619c35b49906bde95d7/static/script/common.js"></script>
<script type="text/javascript">window.roosevelt_params_queue = window.roosevelt_params_queue || [{channel_id: 'dk', channel_label: '{tistory}'}]</script>
<script type="text/javascript" src="//t1.daumcdn.net/midas/rt/dk_bt/roosevelt_dk_bt.js" async="async"></script>
<script>window.tiara = {"svcDomain":"user.tistory.com","section":"글뷰","trackPage":"글뷰_보기","page":"글뷰","key":"182830-17","customProps":{"userId":"0","blogId":"182830","entryId":"17","role":"guest","trackPage":"글뷰_보기","filterTarget":false},"entry":{"entryId":"17","entryTitle":"Browser Center Layer","entryType":"POST","categoryName":"WS & SCript","categoryId":"107649","serviceCategoryName":null,"serviceCategoryId":null,"author":"186251","authorNickname":"Ming's","blogNmae":"Ming's Fragment","image":"","plink":"/17","tags":[]},"kakaoAppKey":"3e6ddd834b023f24221217e370daed18","appUserId":"null","thirdProvideAgree":null}</script>
<script type="module" src="https://t1.daumcdn.net/tistory_admin/frontend/tiara/v1.0.6/index.js"></script>
<script src="https://t1.daumcdn.net/tistory_admin/frontend/tiara/v1.0.6/polyfills-legacy.js" nomodule="true" defer="true"></script>
<script src="https://t1.daumcdn.net/tistory_admin/frontend/tiara/v1.0.6/index-legacy.js" nomodule="true" defer="true"></script>
</body>]]>