I keep getting the error "This page contains both secure and nonsecure items error" how do I get rid of this?

Most likely you have an image (or a frame or some other content on the page) that is not under a https://url.

The browser is warning you that you are pulling SOMETHING on the page non-securely (http:// is the non-SSL connection to the server instead of https://).

Tip: You can click on "view source" in your web browser and then search for http://. You'll will likely spot it quickly,

Here is an example:
Say, you have a few pictures on your secure page. Normally you would call your pictures like this: <img src="http://www.yoursite.com/picture.jpg" />
Of course this will cause the pop-up browser error when viewing a secure page.
The remedy would be to do it like this:
<img src="https://www.yoursite.com/picture.jpg"/>