<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>W3Cschool教程(w3cschool.cn)</title>
<script>
function displayResult(){
var x=document.getElementById("pwd").value;
alert(x);
}
</script>
</head>
<body>
<form>
密码: <input type="password" id="pwd">
</form>
<button type="button" onclick="displayResult()">显示值</button>
</body>
</html>