我希望在用戶單擊“名稱”、“電子郵件”或“消息”框之前不顯示 errName errEmail errMessage 文本。另外我想在按下提交按鈕之前不顯示 $result 。截至目前，即使用戶沒有與提交表單交互，它也只顯示 errName、errEmail、errMessage 和警報。<?phperror_reporting(E_ALL);ini_set('display_errors', 1);global $result;if (isset($_POST["submit"])) {    $errName ="";    $errEmail ="";    $errMessage ="";    $result="";    $name = $_POST['name'];    $business = $_POST['business'];    $email = $_POST['email'];    $message = $_POST['message'];    $from = '------';    $to = '-----';    $subject = 'Message from user on website';    $body ="-------";}// Check if name has been enteredif (!isset($_POST) || !key_exists('name', $_POST) || !filter_var($_POST['name'])) {    $errName = 'Please enter your name';}// Check if email has been entered and is validif (!isset($_POST) || !key_exists('email', $_POST) || !filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)) {    $errEmail = 'Please enter a valid email address';}//Check if message has been enteredif (!isset($_POST) || !key_exists('message', $_POST) || !filter_var($_POST['message'])) {    $errMessage = 'Please enter your message';}// If there are no errors, send the emailif (!isset($errName) && !isset($errEmail) && !isset($errMessage)) {    $result .= '<br><div class="alert alert-success">Thank You! We will be in touch</div>';} else {    $result .= '<br><div class="alert alert-danger">Sorry there was an error sending your message. Please try again later.</div>';}