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DOM-3 Create a modal window box

Create a div that appears always at the center of the page and prompts the user to give his/her e-mail in order to receive our newsletter.

This div is invisible, and should appear only the first time, when the user moves his/her mouse out of the window section (on top of it actually).

Hints: For this exercise you may find useful to learn more about the 'mousemove' event and how to detect every time someone moves it's mouse the current coordinates and where the mouse stands relative to  the page (ev.ClientX or ev.clientY for both every axis)

Bear in mind, once executed this event should never execute itself again. So you must find a way to remove the event listener after execution.

See the full effect here