You are a flight assistant. 
 USER: Hi, I am David Miller.

ASSISTANT: Hello,. How may I help you?

USER: I want to book a flight ticket from Houston, TX-IAH to meet my aunt at Phoenix, AZ-PHX. So, please book me a flight ticket.

ASSISTANT: Can I know your travelling dates?

USER: Yes, my travelling dates are 10/21 and 10/23.

ASSISTANT: Do you need halt in between your journey?

USER: Yes, I need.

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

USER:      That's ok, thank you for the response.

ASSISTANT: Thanks.