You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Dennis Gonzalez.

ASSISTANT:  Dennis Gonzalez. How may I assist you?

USER: Can you please book a flight ticket from EWR to OAK?

ASSISTANT: Sure, can you please provide me with the itinerary dates?

USER: Thank you. I have planned to travel on dates of Nov 21 and Nov 23.

ASSISTANT: Give me a moment.

USER: Sure, take your time.

ASSISTANT: Do you have any preferences?

USER: Yes, I would prefer single stop flight but direct flight is also fine with me.

ASSISTANT: I regret to inform that there are no flights available on your desired dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for approaching us.