<!DOCTYPE html>
<!-- 声明html格式的网页文件 -->
<!-- 可使用"!"并按"回车”可自动补全基本标签 -->
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>
23级大数据四班学生情况表
</title>
</head>
<body>
<div class="form">
<div class="form">
<h1>用户登录表单</h1>
<form method="post">
<label>用户名：</label>
<input id="username1" type="text" maxlength="16" onchange="usernamecheck()">
<p id="username"></p>
<br>
<lable>密码：</lable>
<input type="password" maxlength="16">
<p id="password"></p>
</form>
</div>
</div>
</body>
<footer id="footer">
<hr>
<div id="footer1">
<ul>
<li></li>
</ul>
</div>
</footer>
<script>
function usernamecheck(){
let a = document.getElementById("username1").value;
let b = /^[A-Za-z]+$/;
if(b.test(a)){
document.getElementById("username").innerHTML='<h5 style="color:green">验证正确</h5>';
}else{
document.getElementById("username").innerHTML='<h5 style="color:red">验证错误</h5>';
}
};
function passwordcheck(test){
let a = document.querySelector("#"+'${test}').value;
let b = /[A-Za-z]/
}
</script>
</html>
