You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am Brenda Williams, can you help me to book a direct flight?

ASSISTANT: May I know your travelling dates?

USER: My journey dates are 12/14 and 12/16.

ASSISTANT: Ok, can you please tell me your travelling airport codes?

USER: My source and destination airport codes are SFO and SEA.

ASSISTANT: Sorry, no flights found on your preferable dates.

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

ASSISTANT: Thank you for reaching us.