In that case you could just use:
<?php
if (!isset($_POST["dropdownws"])) {
$removeBegins[] = "CoreSupport";
}
?>
But you would still have to give the checkboxes a value. To remove the label for a particular column but keep it's value you could use:
if (strpos($pkey,"linbreak") === 0) $pkey = "";
Just add it after the other IF statements, but before the value is displayed.