New codepen example - modal window.

In user interface design for computer applications, a modal window is a graphical control element subordinate to an application's main window. It creates a mode that disables the main window, but keeps it visible with the modal window as a child window in front of it.
This is my example with a modal window created on codepen website.
The example is very simple.
The html5 source code is created with classes and id's.
The css file make all style for this tags.
The javascript use all of this to open the modal window, use click to close the window.
The Cancel and Add buttons not work with the java script.