I have a really basic problem and I can't find my mistake?
When I want to echo out zone_field
(input field), i get this error: Notice: Undefined index: zone_field in ...
HTML CODE
<form action="./includes/insert_data.php" method="POST">
<div id="zone_area">
<p><input type="text" value="test" name="zone_field" id="zone_field" placeholder="Enter a zone" autocomplete="off"></p>
</div>
<div id="button_area">
<p><input type="submit" value="Start" id="toggle_btn" name="toggle_btn"></p>
</div>
</form>
PHP Code
<?php
include_once("./conn.php");
echo $_POST['zone_field']; //can't echo out the value of the input
?>