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Question

while using $_SERVER in php i am getting this error 403.

i am using three files

index.php:-

<?php

    include 'header.inc.php';

    if(isset($_POST['submit'])){
        echo 'process 1';
    }

    ?>

header.inc.php:-

<?php

$_script_name= $_SERVER['SCRIPT_NAME'];


?>

<form action="<?php echo $script_name ?>" method="POST">
    <input type="submit" value="log in">
</form> 

another.inc.php:-

<?php
include 'header.inc.php';

if(isset($_POST['submit'])){
    echo 'process 2';
}

?>

after clicking of log in button i displayed the page with error 403

this is the page showing error

please help me hoe to solve this problem. I am searching for the correct solution for last 2 days but didnt find any working solution.