You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Lisa Roberts.

ASSISTANT: How may I aid you?

USER: Can you please book me a ticket from IAD to OAK?

ASSISTANT: Sure, may I know your trip dates?

USER: My travel dates are from Aug 29th to Aug 31st.

ASSISTANT: May I know your connection limit?

USER: I want a single connection in between my journey.

ASSISTANT: Is there any class preferences?

USER: No.

ASSISTANT: Do you have any specifications?

USER: I want to return in the afternoon.

ASSISTANT: Sorry, there are no flights found on your travel dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.