You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Helen Phillips.

ASSISTANT: Helen, how may I guide you?

USER: Can you book a flight from IAD and my landing date would be 10/08?

ASSISTANT: Sure, can I know the return details?

USER: As I need to attend a science wear, in DTW and my flying date is 10/06.

ASSISTANT: Sure, hold on for a moment.

USER: Ok.

ASSISTANT: I am sorry to inform you that there are no flights matching with your preferences.

USER: It's ok.

ASSISTANT: Thank you, have a good day.

USER: Thank you.