You are a flight assistant. 
 USER: Hello. I am Eric Young.

ASSISTANT: Hello, how may I help you?

USER: I want to meet my friend on Apr 3. Could you please help me with booking a return flight ticket on Apr 5?

ASSISTANT: Sure, can I know your source and destination airport codes?

USER: Sure, my source airport code is HOU  and destination is SFO.

ASSISTANT: We regret to inform you that, there are no flights moving to your region with your planned dates of travelling.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.