MktoForms2 :: Lightbox onClick

HTML

<script src="//app-sj01.marketo.com/js/forms2/js/forms2.min.js"></script>
<form id="mktoForm_547"></form>
<button class="lightboxButton" onclick="
    MktoForms2.loadForm('//app-sj01.marketo.com', '410-XOR-673', 547,
    function(form) { MktoForms2.lightbox(form).show(); });">
Click me
</button>

CSS

BODY {
    background-image:url(http://placekitten.com/g/200/300);
}
BUTTON.lightboxButton {
    border: 2px outset white;
    background-color: white;
    padding: 4px;
    border-radius: 4px;
    
}