Once you hit the submit button, a dialog box pops up and asks about secure and non-secure item. Is this necessary and how/where in the coding do I change this? Remember, you're dealing with a complete newbie when it comes to php.
Are you using https and submits the form to a http url?
https.
I believe this occurs if your form points to a https url, but the targe page includes non-secure http url items (iframes, images, etc.). If you change those other URLs to also use https, then you should get rid of that message.