I want to check if the post if filled or not (post variable empty or not) I'm using "isset", and it just does not seem to work, everytime i submit the form it says filled even when the form is not filled.

PHP code :

<?php if (isset($_POST["submit"])) { echo "filled"; } else { echo "not filled"; } ?> 

HTML code :

<form method="post"> <input type="text" name="username" /><br><br> <input type="submit" name="submit"> </form> 

when i printed $_POST, it says :

[username] => [submit] => Submit