You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I would like to book a flight ticket from DTW to OAK to meet my uncle on his birthday. Can you please help me with booking a flight ticket?

ASSISTANT: Sure, may I know your good name?

USER: I am Emily Harris.

ASSISTANT: Could you please share your trip dates?

USER: Sure, my travelling dates are May 9 and May 11.

ASSISTANT: Do you have any preferences?

USER: Yes, I want to return in the evening.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry, there are no flights available as per your requirements.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.