Well what happens is this, when your browser initializes the SSL engine, it checks every object on the page has been loaded over the same protocol, regardless of the URL preceding it. So anything which isn't loaded breaks this process and on chrome (and IE) You get the pop up saying "Elements on this page may be insecure". The simplest way to do it is this, go through each file you use (and each image) and host it on your own server, accessing it through a relative path, ie. "/images/banana.jpg" instead of "https://banana.com/images/banana.jpg. It could also be any .js files you link to, for instance your jquery version, etc. if you can't find an https version to load it off, then also stick it on your own server.

It costs more in bandwidth, but if you are serious about your clients security, it's great to say that "everything we host here is secured on our own servers" and also gives you constant control over every element.