js函数

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>div块布局</title>
<style>

</style>
<script>
window.onload=function(){
      var ok=document.getElementById("box");
          ok.onclick=function(){
             alert("加载完了！")
          };
};
</script>
</head>

<body>
<div id="box">ok</div>
</body>
</html>