我的目的:如果用户字段和密码字段为空,我想停止表单提交.这是我正在尝试的代码:
<!DOCTYPE html>
<html>
<head>
<script>
function doit() {
var usr = document.getElementById('ur').value;
var psw = document.getElementById('pw').value;
if ((usr.trim() == '') && (psw.trim() == '')) {
alert("cannot Submit form");
return false;
}
}
</script>
</head>
<body>
<form action="post.php" method="post" onsubmit="doit()">
User:
<input type="text" id="ur" name="user">
<br>
<br> Pass:
<input type="password" id="pw" name="pass">
<br>
<br>
<button>Submit</button>
</form>
</body>
</html>
我正在学习JavaScript.如果你纠正代码并稍微解释为什么它不起作用将会有所帮助.
javascript ×1