add the following code at line 1 to reset the posted value to empty if it is equal to either of those strings:
<?php
if($_SERVER['REQUEST_METHOD'] == "POST") {
if($_POST['editorField'] == " " || $_POST['editorField'] == "<br/>" || $_POST['editorField'] == "#160;" || $_POST['editorField'] == "\r\n") {
$_POST['editorField'] = "";
}
}
?>
you will need to edit "editorField" to use the name of your HTML Editor instance.