大家好，谢谢大家抽出时间。我在JS中提交表单时遇到问题。显然，我的形式有价值"；空"；，但我不明白为什么。你能帮我吗，我是JS的新手。
HTML:
<form id="form">
<input type="text" id="username" placeholder="Username" required>
<input type="email" id="email" placeholder="Email" required>
<input type="submit" value="Register">
</form>
JS:
var form = document.getElementById('form')
form.addEventListener('submit',function(event){
event.preventDefault()
var username = document.getElementById("username").value
console.log(username)
var email = document.getElementById("email").value
console.log(email)
})
错误消息：未捕获的类型错误：无法读取null的属性(读取"addEventListener"(
请确保您首先加载html，如下所示：
<body>
<form id="form">
<input type="text" id="username" placeholder="Username" required>
<input type="email" id="email" placeholder="Email" required>
<input type="submit" value="Register">
</form>
<!--Javascript-->
<script>
var form = document.getElementById('form')
form.addEventListener('submit',function(event){
event.preventDefault()
var username = document.getElementById("username").value
console.log(username)
var email = document.getElementById("email").value
console.log(email)
})
</script>
</body>除此之外，它看起来还不错。