You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please book the ticket from HOU to BOS? As I'm planning to visit Boston.

ASSISTANT: Sure, I am here to help you. Could you please tell me your name?

USER: Sure, my name is Elizabeth Davis.

ASSISTANT: Thank you. Please let me know your travel dates.

USER: I would like to depart from my source location on 21st Sept and return back by 23rd Sept.

ASSISTANT: Noted. Do you have any connection limit preference for this trip?

USER: I prefer single connected flight.

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no flight available on your preferred travel dates.

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

ASSISTANT: You are most welcome.