Below is the link formatting for the iframe needed in your site.
Infusionsoft will be a form that is submitted prior to reaching the page with this url “iframed” in.
You will need to create a form in Infusionsoft to capture the lead’s information prior to reaching this page. This form will need to contain the fields required. I recommend using the First Form to capture the basic contact details. Then use a 2nd form to capture details for the quote, then have the iframe page.
So your php script will prepopulate the 2nd Infusionsoft form with values from the first form, then populate query string values in the iframe from Infusionsoft’s form(Translating Infusionsoft values into Quoteits.)