Javadoc
If an event is cancelable, the preventDefault
method is
used to signify that the event is to be canceled, meaning any default
action normally taken by the implementation as a result of the event
will not occur. If, during any stage of event flow, the
preventDefault
method is called the event is canceled.
Any default action associated with the event will not occur. Calling
this method for a non-cancelable event has no effect. Once
preventDefault
has been called it will remain in effect
throughout the remainder of the event's propagation. This method may
be used during any stage of event flow.