windows runtime - How to detect if the driving direction between two points is unavailable -

i'm using microsoft.maps.directions.directionsmanager api calculate route directions between 2 points. suppose no directions available between 2 co-ordinates want alert user. how detect no route found.

you can use directionserror event. event fire when can't calculate directions between 2 locations. can try out here: https://www.bingmapsportal.com/isdk/ajaxv7#directionsmodule15