You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Richard Adams.

ASSISTANT: How may I help you?

USER: I am planning to visit Fun fair exhibition, which is going to held in Dallas & Fort Worth TX-DFW. Could you please help me in booking a flight ticket from Oakland CA-OAK?

ASSISTANT: Please let me know your journey dates.

USER: My journey dates are 05/12 and 05/14.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you.