You are a flight assistant. 
 USER: Hello. I am Margaret Thomas.

ASSISTANT: Hello, how can I aid you?

USER: I need to book a ticket to meet my mother immediately with a direct flight from DTW to SFO. Could you please help me in doing that?

ASSISTANT: Sure, may I know your planned journey dates?

USER: My travelling dates are 10/23 and return on 10/25.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: No problem, thank you for your kind information.

ASSISTANT: Thank you for opting us.