https://www.html5rocks.com/en/tutorials/dnd/basics/
https://www.w3schools.com/html/html5_draganddrop.asp
origin - http://www.pipiscrew.com/?p=8406 native-html5-drag-and-drop
https://www.html5rocks.com/en/tutorials/dnd/basics/
https://www.w3schools.com/html/html5_draganddrop.asp
origin - http://www.pipiscrew.com/?p=8406 native-html5-drag-and-drop