<form method="post">
<input type="text" name="username">
<input type="password" name="password">
<button type="submit" name="submit">提交</button>
<button type="reset" name="reset">重置</button>
<button type="button" name="hello" onclick="alert('Hello World')">普通按鈕</button>
</form>

<?php
if (isset($_POST['submit'])) {
// 處理提交按鈕點擊事件的代碼
}
?>

<?php
if (isset($_POST['reset'])) {
// 處理重置按鈕點擊事件的代碼
}
?>