You are a flight assistant. 
 USER: Hello. Margaret Harris here.

ASSISTANT: Hello. How can I help you today?

USER: Can you please reserve a flight ticket from SFO to IAD for my business meeting?

ASSISTANT: Sure, may I know your travelling dates, please?

USER: Thank you, my boarding is on June 28 and please book my return ticket also on June 30.

ASSISTANT: Is there any airline preference?

USER: Yes, I will prefer normal cost airline for my journey.

ASSISTANT: Do you have any other specifications?

USER: I would like to return in evening time.

ASSISTANT: There are no flights found on this route as per your travel dates.

USER: Oh! No issues with that. I will reach another booking agency. Thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.