You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Charles Martinez here.

ASSISTANT: How can I help you?

USER: I want to attend a Marriage in Dallas. Can you please help me for booking the flight ticket?

ASSISTANT: Let me know your travelling dates.

USER: My travelling dates are 04/27 and 04/29.

ASSISTANT: Can I know your airport codes?

USER: My airport codes are SFO and DFW.

ASSISTANT: Do you have any preference?

USER: I want to return on afternoon.

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

USER: Anyway, thanks for the information.

ASSISTANT: Thank you.