Handling Array values - unset or array_pop

I have a post value like this. It is stored in $_POST. Now, I need to remove or unset the last array value i.e [submit] => Add. When I checked in SOF, they asked me to use array_pop. But that didn't work. Any help.

My output:

    [56-1] => 0
    [56-2] => 0
    [56-3] => 0
    [submit] => Add

Expected output:

        [56-1] => 0
        [56-2] => 0
        [56-3] => 0

EDITED:

Here is my code

    <?php 
    $my_array = $_POST;
    foreach($my_array as $key=>$value){
    array_pop($my_array);
    unset($key['submit']);
    }
    print_r($my_array);
    ?>

Thanks,

Kimz

<?php

unset($_POST['submit']);

?>