Popup Pro Not Allowing Java Snippets (Infusionsoft Forms) When Displayed

How do I manage to add the following snippet inside the popup for non-members to join the blog via my inufsionsoft lead forms?

I tried putting it in the Source Code, no dice..just loads blank area for where form should be.

<script type="text/javascript" src="https://nx305.infusionsoft.com/app/form/iframe/a3b56514763ed13c46e2d88f9f87cac2"></script>