Hey Dan,
I tried the steps above and it didn't work for me either. I looked at your test page, and it looks like it works though! In any case, here's what I did to get it working on a non-marketo webpage, based on info here (http://developers.marketo.com/documentation/websites/forms-2-0/). Just replace the bold parts with your info.
<a href="#" id="lightbox-link">LINK</a>
Thank you for this! Spelling it out like this was really helpful.
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Just replace the bold parts with your info.
<a href="#" id="lightbox-link">LINK</a>
<form id="mktoForm_XXXX"> </form>
<script>
var btn = document.getElementById("lightbox-link");
btn.onclick = function(){
MktoForms2.loadForm("//app-XX01.marketo.com", "123-ABCD-000", XXXX, function (form){
MktoForms2.lightbox(form).show();
});
};
</script>