<!-- Paste the following code under Settings - HTML/CSS, HEAD -->
<style>
#submit-in-progress-popup,
#submit-success-popup {
display: none !important;
}
</style>
<!-- Paste the following code under Settings - JavaScript, FOOTER -->
<script>
// Make sure you name the button that will contain the popup -> "popup"
var popupButton = $('.popup-link:contains(popup)');
window.instapageFormSubmitSuccess = function( form ){
popupButton[0].click();
};
</script>