In many cases we have add call out in order to explain parts of equipament. So what i want to do is: click on image and a call out explain and when i click the same image again the call out fade. How can I do that?

Hi Pedro,

It sounds like you want the caption to toggle show/hide each time you click the image. Here's an example of how to set this up:

Rob's method is great!  For anyone interested in a slightly more complex but streamlined method of doing the same thing, here's an example of that - http://share.smartbuilder.com/public/support/toggle-showing.mp4

Both methods work well, so just use the one that makes the most sense to you!