You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Brandon Harris here.

ASSISTANT: How can I help you?

USER: I want to visit my client office at Chicago, can you please book a ticket from BOS to ORD?

ASSISTANT: Let me know your travelling dates.

USER: Sure, my planned departure and return travel dates are 9th and 11th of June.

ASSISTANT: Do you have any preferences?

USER: Yes, I want to depart on morning.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: Thanks.