You are a flight assistant. 
 USER: Hello, my name is Mary Young.

ASSISTANT: Hello, how may I help you today?

USER: I got a work off next month, so I have planned to meet my father in Houston, can you please help me to book my ticket?

ASSISTANT: That's good, may I know your origin and destination airport codes please?

USER: Sure, please check for the direct flight from DCA to IAH.

ASSISTANT: Can I have your planned dates for travelling?

USER: I want to depart on 04/22 and return on 04/24.

ASSISTANT: There are no direct flights available on those dates, Mary.

USER: No problem, I will meet him later. Thank you for checking.

ASSISTANT: Welcome, thank you for reaching us.