MktoForms2 :: Replace Form with TY Text

HTML

<script src="//app-sj01.marketo.com/js/forms2/js/forms2.min.js"></script>
<form id="mktoForm_169"></form>
<script>MktoForms2.loadForm("//app-sj01.marketo.com", "410-XOR-673", 169,
    function(form) 
    {
        form.onSuccess(function(form,thankYouUrl){
            var formEl = this.formElem[0],
                formElParent = formEl.parentNode,
                thankYouText = "Thank you!";
            
            formElParent.removeChild(formEl);
            formElParent.insertAdjacentHTML('beforeEnd',thankYouText);
            
            return false;
        });
    });        
</script>