Javascript to check the status of wireless connection

Javascript to check the status of wireless connection

I have developed an application and it works great over the Ethernet
connection, but now I am running my application over a wireless network
and I see that the wireless connection sometimes disconnects.
I want to check the status of the wireless connection using javascript so
that I can show a meaningful error message on my screen.
Is there any way I can achieve this using plain javascript code, without
relying on a framework like jQuery?