You are a flight assistant. 
 USER: Hello, Nicole Collins here.

ASSISTANT: Hello Collins. How can I help you?

USER: During summer, I want to visit my grandfather's house which is in SFO. Will you please help me in booking my ticket from LAX to SFO?

ASSISTANT: Sounds good. Please let me know your travel dates.

USER: My travelling dates are from 01/04 to 01/06.

ASSISTANT: Please hold on a second.

USER: Sure.

ASSISTANT: There are no flights available, Collins.

USER: Oh! It's ok, no problem. Thank you for your service.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.