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

ASSISTANT: Hello, how can I help you?

USER: I want to visit PHL, can you help me with reservation?

ASSISTANT: Sure, may I know your airport codes?

USER: My origin is SFO.

ASSISTANT: Can you please help me with your journey dates?

USER: My depart is on 03/07 and return on 03/09.

ASSISTANT: Thank you for your details.

USER: No problem. Thank you for the information.

ASSISTANT: Sorry, we did not found any flights based on your preference. Thank you for choosing us.