You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am planning to visit a NASA space center in Houston, so please book a flight ticket from EWR to HOU.

ASSISTANT: Sure, may I know your depart and arrival dates?

USER: My departure day is Jan 16, return day is Jan 18.

ASSISTANT: Can you please share your connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specifications?

USER: My return time should be evening.

ASSISTANT: May I know your name?

USER: My name is Edward Walker.

ASSISTANT: Sorry, there were no flights found on your preferred dates.

USER: Not an issue, thank you.

ASSISTANT: Thank you.