简单PHP注册表只收集NULL值

我正试图使用PHP为一个网站创建一个基本的登录/注册。下面的代码显示我需要config.php，我测试了它，它可以顺利地连接到我的网站。当我进入页面并输入值时，无论我为电子邮件和密码输入什么，它都会显示它们总是匹配的。当我尝试输出email1和email2的值时，它什么也不输出。我认为当你按下提交按钮时，表格没有收集数据。如果有人能看到我做错了什么，我将不胜感激！

<?php
require('config.php');
if(isset($_POST['submit'])) {
    $email1 = $POST['email1'];
    $email2 = $POST['email2'];
    $pass1 = $POST['pass1'];
    $pass2 = $POST['pass2'];
    if($email1 == $email2) 
    {
        echo "Emails match.<br />";
        if($pass1 == $pass2)
        {
            echo "Passwords match.<br />";
        }
        else 
        {
            echo "Sorry, your passwords do not match.<br />";
            exit();
        }
    }
    else 
    {
        echo "Sorry, your emails do not match.<br /><br />";
    }
}
else {
$form = <<<EOT
<form action="register.php" method="POST">
First Name: <input type="text" name="name" /><br />
Last Name: <input type = "text" name = "lname" /><br />
User Name: <input type = "text" name = "uname" /><br />
Email: <input type = "text" name = "email1" /><br />
Confirm Email: <input type = "text" name = "email2" /><br />
Password: <input type = "password" name = "pass1" /><br />
Confirm Password: <input type = "password" name = "pass2" /><br />
<input type = "submit" value = "Register" name = "submit" />
</form>
EOT;
echo $form;
}
?>