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Question

I Have tried many solutions posted on stack overflow and non of them have worked.

It could just be me but i tried it on a separate file and it worked but if i use my current site with nice css it won't work

I Have tried the exact code on LAEPHP and it worked but when i added my code as you can see below it does not display anything when the button is clicked and it does not even refresh the page on click

<form action="" method="post">
    <div class="form-group">
        <label>Username</label>
        <input class="au-input au-input--full" type="email" name="target" placeholder="Example">
    </div>

    <div class="form-group">
        <label>API key</label>
        <input class="au-input au-input--full" type="text" name="key" placeholder="X7UI-9H2D-IZAS">
    </div>

    <?php

        $key= $_POST['key'];
        $send= $_POST['send'];

        if ($send) {
            if (!empty($key)) {
                echo 'The key you entered is ' . $key;
            }
            else {
                echo 'You did not enter a key. Please enter a key into this form field.';
            }
        }
    ?>

    <button class="subscribe btn btn-primary btn-block" name="send" type="submit">Check Key</button>
</form>

Answer 1

The problem I see is that you're checking if the button was sent and isn't "falsy". Since you don't have a value-attribute on the button, it will be an empty string, which is a "falsy" value, meaning that the first if-statement will never evaluate as true.

Try changing your code to:

<?php
// isset() is better since it check if the key exists and isn't null.
if (isset($_POST['send'])) {
    // If you rather put the values in separate variables,
    // you should do it here, inside the if-statement (where we know we
    // got a POST request)

    if (!empty($_POST['key'])) {
        echo 'The key you entered is ' . $_POST['key'];
    }
    else {
        echo 'You did not enter a key. Please enter a key into this form field.';
    }
}
?>