You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: I am Stephen Nelson, can you help me to book a flight to SEA?

ASSISTANT: Sure, please provide your source airport code.

USER: My preferable source airport code is PHL.

ASSISTANT: Please help me with your travelling dates.

USER: My travelling dates are 10/29 and 10/31.

ASSISTANT: Please give me a moment. Stephen, no flights has been found on your journey dates.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.