You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I need to book a ticket from Houston to Las Vegas.

ASSISTANT: Sure, may I know your planned travel dates?

USER: Departure is by Jan, 9 and return date is Jan, 11.

ASSISTANT: May I know your nearest airport codes please?

USER: Airport codes are HOU and LAS.

ASSISTANT: Do you have any limits on number of connections?

USER: I would be comfortable with single stop over.

ASSISTANT: Do you have any another specifications on your journey?

USER: I would like to return in the evening time.

ASSISTANT: May I know your name for the documentation process?

USER: I am Lisa Rodriguez.

ASSISTANT: Sorry no flights are available on your required dates.

USER: Thank you.

ASSISTANT: Welcome, thank you for reaching us.