It's The Goodbye Girl
Not a long movie (111 minutes) but a darn good one
It's from 1977 and it's by Neill Simon...it's about actors and dancers and entertainers and their trials and tribulations...and one woman and her daughter's quest to finally find someone who doesn't do a "runner" as we like to say in Australia
...and how cute was Richard Dreyfuss back in the 70's?
Some interesting trivia about Quinn Cummings, who played Lucy McFadden in the film
She hasn't done any acting for some years in fact she started her own business after inventing a hip-hugger baby carrier....oh...and she has her own blog
Anyway, it's a film I've always liked and I always get a laugh out of it...see if you do too.