php / html表单主题行缺失

Question

使用php代码将表单输入发送到电子邮件时遇到问题。

<?php
$emailTo="testing_testing@gmail.com";
$subject = $POST_['username'];
$content = $_POST['course'] . $_POST['message'] . $_POST['tel'];
$headers = "From: ".$_POST['email'];
mail($emailTo, $subject, $content, $headers);
?>

HTML表单代码：

<form  method="post">
        <input id="username" type="text" name="username" placeholder="Name" required> </br>
        <input id="tel" type = "tel" name="tel" placeholder="Phone no." required></br>
        <input id="email" type="email" name="email" placeholder="Email id" required></br>
        <input list="course" name="course">
        <datalist id="course">
               <option value="IELTS">
               <option value="English Speaking">
               <option value="Computers">
               <option value="Accounting">
               <option value="Fashion Designing">
               <option value="Hospitality and Tourism">
               <option value="General Enquiry">
        </datalist>

    <textarea id="message" name="message" rows="10" cols="30" placeholder="Any Message !"></textarea>

    <INPUT id="submit" type="submit" value="Submit">

</form>

输出：

此代码未设置主题字段，因为它表示 - nosubject。在php代码中，我将username的值指定为主题字段。

Answer 1

问题是您声明了$subject变量：

$subject = $POST_['username'];

应该是

$subject = $_POST['username'];

希望这会有所帮助：）