diff --git a/js/util.js b/js/util.js
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index 0000000000000000000000000000000000000000..b821589dbe07f33c249a56015ac07a7e973db665
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+++ b/js/util.js
@@ -0,0 +1,9 @@
+/**
+* 上古时期的工具函数，可以理解为什么要定义这些函数，但是这个第一行`var D=document;`真是的是一言难尽！
+*/
+
+var D=document;
+function $id(id){return typeof id==='string'?D.getElementById(id):id}
+function $tag(el,tag){return $id(el).getElementsByTagName(tag)}
+var getDocumentHeight=function(){return Math.max(D.documentElement.scrollHeight,D.documentElement.clientHeight)}
+var isIE = (D.all) ? true : false;
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