Trying to get a form-specific hook to fire

[php]
add_action("gform_post_submission_4", "subscribe_textmarks", 10, 2);
function subscribe_textmarks($entry, $form){

//first, let's grab the phone number from the form, it's field 1
$phone = get_post($entry["1"]);

//now let's remotely subscribe to textmarks by calling their API via POST
$response = wp_remote_post('http://help.api2.textmarks.com//Anybody/invite_to_group/', array(
	'method' => 'POST',
	'headers' => array(),
	'body' => array( 'api_key' => 'chrislema_com__72225807', 'tm' => 'WORDPRESS', 'user' => $phone )
    )
);
}