老师，帮忙看下对吗

来源：4-9 编程练习

慕的地5368065

2021-05-24 12:45:18

<!DOCTYPE html>
<html>
    <head>
    <meta charset="UTF-8">
    <title>onload</title>
    <script type="text/javascript">
    window.onload=function(){
        Obtn=document.getElementsByTagName('input')[0];
        Obtn.onclick=function(){
            Obtn.style.color="red";
        }
        Obtn.onmouseleave=function(){
            Obtn.style.color="gray";
        }
    }
     //补充代码
    </script>
</head>
<body>
<input type="button" value="点击改变按钮字体颜色" >
</body>
</html>