Fired when the code in a <script> element declared in an HTML document is about to start executing. Does not fire if the element is added dynamically, eg with appendChild().
"online" event is fired on the <body> of each page when the browser switches between online and offline mode. Additionally, the events bubble up from document.body, to document, ending at window. Both events are non-cancellable (you can't prevent the user from coming online, or going offline).
The pointerLockElement property provides the element set as the target for mouse events while the pointer is locked. It is null if lock is pending, pointer is unlocked, or the target is in another document.
Returns the first element within the document (using depth-first pre-order traversal of the document's nodes|by first element in document markup and iterating through sequential nodes by order of amount of child nodes) that matches the specified group of selectors.