When you open node-play for the first time in your browser or if you select Upload from the main menu you are presented with the possibility to upload a file.
Use the button Select Files to navigate to your disk and select the media file you want to publish.
Use the Start button to begin the upload.
In case you need you can pause or quit your upload.
In case of a transient error you can restart your upload.
You can safely navigate inside the node-play web site while your upload are running and the will continue.
In case however should you navigate away from the site the uploads will end prematurely.