Robin Williams helps teenage co-star get a date for prom

The late great Robin Williams helped his teenage co-star, Skyler Gisondo, get a date for prom with a little help from Ben Stiller and Crystal the monkey.

Gisondo, who plays Stiller's son in the Night at the Museum: Secret of the Tomb, was away from home filming the third movie in the series when all of his friends were at home asking girls to the prom.

In what he described as "the most awesome three minutes of my life", the 18-year-old was blown away by the charm and wit of his co-stars.