Good advice all around. Radio is a good first response in any case,
unless you're in a "kiting" situation, in which case the tow pilot
must release as fast as he can. If the glider is not kiting and the
tow plane can clear obstacles at the end of the runway, please try not
to act hastily. The advice to be calm on the radio is good. If you
cannot think of the glider's call sign (happened to me once), just say
"spoilers, spoilers, spoilers". That should get the message across.
Fred