Which episode had Rhoda going into an office and the receptionist had a sign on her closed window that said "Don't Knock on the Glass?"

Which episode had Rhoda going into an office and the receptionist had a sign on her closed window that said "Don't Knock on the Glass?"


I don't recall the name of the episode, but it was season 5, when Ida was dating her younger doctor, I believe.

Thank you. I appreciate it!