With multiple modals, backdrop is showed behind the first

Created by: willianbdaiprai

When you have multiple opened modals, the backdrop of the last opened modal is showed behind the first modal. It's a z-index issue I think.

Here you can see the problem: http://bootply.com/86958

I propose a fix here: http://stackoverflow.com/questions/19305821/bootstrap-3-0-multiple-modals-overlay

Edit: in IE 10, the behind modal is unlocked (you can change text, click buttons, etc). Chrome and Firefox are locked.