The iframe diplays well, except when you get to make the secure payment, the on4.com domain changes to a secure payment domain (secure.voice-pay.com). This means the iframe is offset.
Is there someway of changing the size of the iframe, or maybe just changing the sites URL to another page which was the iframe the correct size?
I’m afraid not. If you have a page that contains an iframe, there can be no “communication” between the parent and the contents of the iframe. Meaning, it’s not really possible to say “if this happens in the iframe contents, do this on the parent page” or vice versa.