HTTP authentication PHP and HTML form
<p>Good morning! I have some problem with HTTP authentication with PHP. As I found in different posts, after the form's submit I tried this PHP code:</p>

<p><strong>PHP</strong> </p>

<pre><code>&lt;?php 
$us = 'name';
$pswd = 'pass';
function verify($a, $b) { return ($a==$us &amp;&amp; $b==$pswd);};
$user = $_SERVER['PHP_AUTH_USER'];
$password = $_SERVER['PHP_AUTH_PW'];
if(!isset($user) || verify($user, $password)==false) {
    header('WWW-Authenticate: Basic realm="MyRealm"');
    header('HTTP/1.1 401 Unauthorized');
    exit;
}
else{
    echo 'Correctly authenticated';
}
?&gt;
</code></pre>

<p>When I click the submit botton form from HTML a popup appears asking me (again) username and password. Why? I think that in some ways I've to set the PHP_AUTH_USER in $_SERVER with the value in the input, but I don't know how.<br>I think that I've done a mistake when I send the data from the form because I'm still using the post method. What method I have to use?</p>

<p><strong>HTML</strong></p>

<pre><code>&lt;br&gt;
&lt;form method="post" action="page.php"&gt;
   &lt;input type="text" name="user"&gt;
   &lt;input type="password" name="password"&gt;
   &lt;input type="submit"&gt;
&lt;/form&gt;
&lt;br&gt;
</code></pre>

<p>I never did it before, any tips on how check data on server side or something else are welcome!</p>