Attachment link to Post ID

i am using

<?php //Get image genererated from form
$argsThumb = array(
    'order'          => 'ASC',
    'post_type'      => 'attachment',
    'post_parent'    => $post->ID,
    'post_mime_type' => 'image',
    'post_status'    => null
);
$attachments = get_posts($argsThumb);
if ($attachments) {
    foreach ($attachments as $attachment) {
        //echo apply_filters('the_title', $attachment->post_title);
        echo '<a href='.wp_get_attachment_url($attachment->ID, 'thumbnail', false, false).'><img src="'.wp_get_attachment_url ($attachment->ID, 'thumbnail', false, false).'" /></a>';
    }
}
?>

to display image attachments that were added to posts created with formidable pro.

I want to be able to have when clicked, the image link to the post id, not to the image.

Does anyone know how i have to edit the above code so that when clicked the image will link to the post its attached to and not its own image url?

Thanks a bunch.